Yuriy O. Averkov  
Head. Department №23
Doctor of physical and mathematical sciences
Senior research fellow
Tel. (+ 38-057) 7634-321
E-mail: yuriyaverkov@gmail.com

Portfolio


The subjects of research

Sorry, this entry is only available in Русский and Українська.

Scientific and technical development

2005

The whispering gallery mode dielectric resonator of a truncated cone shape was studied for the first time. The possibility of individual measuring the surface resistance of HTS films was shown experimentally in the millimeter wave band using resonators in the form of a cone and a hemisphere, which allows one to get rid of procedure with three pairs of films (<Barannik A.A., Bunyaev S.A., Cherpak N.T.).

It is shown that in the disk QDR a capillary filled with a lossy liquid, strong influence of liquid on the frequency of the field in the cavity is observed only at a certain layer thickness x, close to the value lliq/4, which depends on the dielectric parameters of the test substances and determines the maximum diameter of a capillary dmax ~ 2x (Lavrinovich A.A.)

2006

A linear temperature dependence of the microwave conductivity of optimally doped HTSC YBa2Cu3O7-d film was obtained at low temperatures (Barannik A.A., Cherpak N.T.).

2007

A new nonresonant radio-physical method for studying of complex conductivity of high-temperature superconductors was justified and developed. The developed method allows studying of high-temperature superconductors in extreme temperature conditions, which is essential to study the properties of high-temperature superconductors at the critical temperature and above it, i.e. in a normal state. The first results on the fluctuation conductivity investigation at a temperature from 115 K and below were obtained. The method may be useful for the study of other condensed matter, complex conductivity or permeability of which varies under the influence of external factors (Gubin A.I., Lavrinovich A.A, Cherpak N.T.)

2008

It was found that the residual surface resistance (i.e. resistance at T ®0) in superconductors YBa2Cu3O7-d varies as a function of frequency ω3/2 for films and single crystals, which suggests the intrinsic nature of this effect. These results were obtained using a new measurement technique of impedance properties investigation of high-Tc superconductors, proposed and developed by the authors on the basis of WGM sapphire resonators (Cherpak N.T., Barannik A.A., Bunyaev S.A.)

2009

The temperature dependence of the microwave surface resistance and surface reactance of new superconducting single crystal Ba (Fe1-xCox) 2As2 was obtained for the first time. These results were obtained using the proposed and developed by the authors technique of measuring impedance properties of new superconductors such as Fe-pnictides (Barannik A.A., Cherpak N.T., Torokhtii K.I.).

2010

The technique of processing the experimental results of measurement of the temperature dependence of the surface impedance of small sized superconductors by means of the WGM sapphire resonators was developed.The temperature dependence of the penetration depth, density of superconducting electronic component and density of quasi-particle component for a new superconducting single crystal Fe-pnictide, namely superconductor Ba (Fe1-xCox)2As2 was obtained from the results of measurements in the millimeter wave band. The results show that the superconductor is not a BCS-type superconductor. According to the analysis of the temperature dependence of the penetration depth and the density of superconducting electronic component, symmetry of the order parameter can be s + / s- or nodal (nodal), that is, with the nodes of the gap function. Preliminary analysis of the temperature dependence of the quasi-particle liquid density shows no coherence peak, which does not coincide with those of other authors. This feature requires further investigation. The study of electromagnetic characteristics of sapphire QDR (i.e. WGM resonator) with HTS films as CEP and the radial gap with the measured superconducting sample inside of it was continued (Barannik A.A., Cherpak N.T.).

The theoretical analysis and simulation of the method of studying microwave response of HTS and related materials by measuring the reflectance of the sample during the propagation of the wave through the waveguide corner section with the sample under test were carried out at grazing angles of incidence. The expediency of using the corner section with smooth transitions, in which the height of the waveguide varies according to the hyperbolic tangent, was shown. The conditions for increasing the sensitivity of the method were determined and the optimal conditions were chosen based on the relationship between the height of the sample placing relative to  the waveguide, the angle of incidence and the linear dimensions of the test sample (Gubin A.I., Lavrinovich A.A.)

The HTS film-based transmission line of planar waveguide type with nonlinear properties was created. The characteristic power of the signal was found experimentally, at which the nonlinear dependence of the propagation of the input signal was observed. The ability to control non-linearity was demonstrated experimentally by passing DC through the line. (Gubin A.I., Lavrinovich A.A., Cherpak N.T.)

2011

  1. A correlation between the quasiparticle scattering rate, the London depth and surface impedance for an arbitrary value of the mentioned rate in the Drude formula was generalized. The technique of the quasiparticle scattering rate determination in unconventional superconductors based on the experimental measurement results of the superconductors surface impedance dependending on temperature was elaborated. An estimation in a superconducting single crystal Ba (Fe1-xCox)2As2 was obtained (Cherpak N.T., Barannik A.A.), The A modified coplanar waveguide transmission line based on epitaxial HTS film with nonlinear impedance was made jointly with the staff of Peter Gruenberg Institute, Forschungszentrum Juelich, Germany to continue studying peculiarities of such transmission lines with nonlinearity controlled by direct current (Gubin A.I., Lavrinovich A.A.)

2012

  1. The relationshipbetween the effectiveand intrinsic(bulk) surface impedance was obtained for superconductingthin filmsunder condition when the microwave fieldat the surface ofthe filmhas an oppositedirectionrelative to the fieldat the oppositesurface of the film.The relationshipexpandsoptionsin thelocationof the thin filmin a microwave cavityandtherebyextends the capabilities ofthe studying superconductingthin films(Cherpak N.T.). The temperature dependence of the effective microwave impedance of the thin film superconducting FeSexTe1-x was obtained experimentally. Other composites of this family of superconductors were studied abroad. The experimental data allow determining the main characteristics of the FeSexTe1-x electronic system (Barannik A.A.). A mm-wave band stable oscillator based on a small-sized semiconductor module was created. The  analogues in Ukraine are absent. The oscillator was created to conduct studying of microwave properties of superconductors and bioliquids using WGM resonator technique developed in IRE NASU (Gubin A.I.) 

2013

On the basis of the microwave impedance measurements, the temperature dependence of the complex conductivity of superconducting chalcogenide FeSexTe1-x was obtained and analyzed. The magnetic penetration depth exhibits a power-law behavior of, with an exponent n ≈ 2.4 at low temperatures, which corresponds to idea of s+/- symmetry of order parameter by analogy with pnictide BaFeCoAs where n=2.8. The first publication on microwave study of FeSexTe1-x film was prepared. The results are important to clear up the basic properties of novel unconventional superconductors.

The step dependence of microwave loss on temperature was found during studying nonlinear peculiarities of HTS-based coplanar transmission line (waveguide). The width of a step feature depends on power of pulsed microwave field. Nature of the peculiarity has not cleared up and demands the further research.The obtained results can have practical importance for HTS-based microwave technology and be important to study nonlinear properties of superconductors in microwave fields.

A microwave characterization technique on the basis of a high-quality whispering-gallery mode (WGM) sapphire resonator with a microfluidic channel filled with the liquid under test was developed. The complex permittivity of aqueous solutions of proteins (cytochrome C, albumines) and glucose was measured depending on concentration with a high accuracy. The measurement technique is original. The results can be fundamental of a novel approach to dielectrometry of biological liquids on the whole and to dielectrometry of liquids of small volume specifically (Barannik A.A., Gubin A.I., Lavrinovich A.A.,Protsenko I.A., Kharchenko M.S., Cherpak N.T.).

2014

  1. By continuingstudy of the nonlinear properties ofa coplanartransmission line (CPL) on the basis ofHTSCYBaCuOthin film, the authors found quenching transition to a stronglydissipative state of CPLby passing DC through it. An important feature ofthe observed effectis itsnon-destructivecharacter. In this case the superconducting propertiesare restored when thepower of the microwavesignal orDCvaluedecrease. The authors assumethat thenature of the effectmay be due toself-heatingHTSthinfilmstructurecaused bymagnetic flux flowwith an overalleffect of microwaveand DCcurrents.The effectmay havescientific significanceinthe field of nonlinearradio physics andapplied importancefor microwavetechnology(Gubin A.I., LavrinovichA.A.,CherpakN.T.).
  2.  By developing microwave dielectrometry based on high-Q WGM resonators for study of lossy bioliquids with small volumes, the authors have developed an approach to solving the inverse electrodynamic problem under conditions when the Q-factor and frequency of the resonator depends on both the real and the imaginary part of permeability of liquid under test. The method can be of practical significance for the study and testing bioliquids of small volumes (Barannik A., Gubin A.I., Protsenko I.A.).
  3.  The temperature dependence of the complex electron conductivity was obtained and the value of two energy gaps were found for chalcogenide superconductor The study was conducted for a thin (100 nm) epitaxial film. The results are qualitatively consistent with the results in the study of a single crystal FeSeTe by other authors, but there are significant differences that need to continue with the aim of consensus conclusions (Barannik A.A., Cherpak N.T.)

History of the Department

Sorry, this entry is only available in Русский and Українська.

Main results of all-time

Sorry, this entry is only available in Русский and Українська.

Scientific results

2005

  1. The procedure of the theoretical investigations for the new resonance structure (waveguide-coaxial resonator) has been proposed. Numerical calculations of the eigen frequencies and Q-factors of the waveguide-coaxial resonator for the centimeter band were carried out. Bilous R.I., Motornenko A.P.
  2. The problem of Cherenkov radiation by a moving electron bunch above a left-handed material has been theoretically examined. Over the frequency range where the refraction index of the composite medium is negative the surface electromagnetic waves can be excited over one and the same frequency range with bulk electromagnetic waves. In this frequency range the surface waves have negative dispersion and their total time-averaged energy flow density is also negative. Averkov Yu.O., Yakovenko V.M.
  3. Based on the results of the investigation of high-Q hemispherical dielectric resonator (DR), a new type of resonator – barrel-shaped DR obtained by the cross section of the dielectric hemisphere. The results of its research electromagnetic characteristics shown that compared to hemispherical DR discharged its frequency spectrum (no higher azimuthal modes). At comparison with the known half-disk resonator the barrel-shaped DR is a more high-Q resonant system due to less radiation energy losses. In order to improve the resolution of the measurements suggested the use of the barrel-shaped DR as the basic cell of a millimeter wave dielectrometer for measuring liquids with high losses of the microwave field. It has been established that there is a connection between the electromagnetic characteristics of DR and conditions of excitation by the concentrated sources of radiation. Kogut A.E.
  4. Electrodynamic problem was solved based on Maxwell's equations with taking into account a magnetic current of radial magnetic dipole. The field components of the forced H modes of resonator under test were determined. The computer program was compiled and debugged. This program allows to determine the resonant frequency and the quality factor of resonator with the forced H modes and its field structure and energy density distribution on the surface of hemisphere and on the conducting plane outside hemisphere. A numerical experiment on the study of hemispherical Teflon resonator with radius of 39 mm that is placed on a perfectly conducting infinite plane was made. Filippov Yu.F., Prokopenko Yu.V.
  5. The interaction of electrostatic oscillations with the flux of the charged particles passing parallel or perpendicular to the interface of the structure has been studied in the hydrodynamic and kinetic approaches. The structure consists of the plasma layer bordering the media with different properties. The spectra and collisionless decay (growth) of oscillations in such a system have been obtained. The interaction of electromagnetic oscillations of the periodically inhomogeneous medium with electron beam has been considered. The hydrodynamic theory of the interaction of the space-charge waves in the beam with electromagnetic oscillations has been built. The conditions of instabilities and the conditions of the stabilization of the instabilities have been found. Khankina S.I., Yakovenko V.M.
  6. For the first time the theoretical investigations of the nonlinear features of the limited periodic anisotropic materials have been performed . Nonlinear excitation of the second harmonic of the fall of the first harmonic on the semi-bounded nonlinear periodic structure was considered. It made possible to explain the experimental results for the measuring parameters of the non-linear features of periodic systems in mm and the terahertz range. Bulgakov A.A., Shramkova O.V.
  7. The whispering gallery mode dielectric resonator of a truncated cone shape was studied for the first time. The possibility of individual measuring the surface resistance of HTS films was shown experimentally in the millimeter wave band using resonators in the form of a cone and a hemisphere, which allows one to get rid of procedure with three pairs of films Barannik A.A., Bunyaev A., Cherpak N.T.
It is shown that in the disk QDR a capillary filled with a lossy liquid, strong influence of liquid on the frequency of the field in the cavity is observed only at a certain layer thickness x, close to the value lliq/4, which depends on the dielectric parameters of the test substances and determines the maximum diameter of a capillary dmax ~ 2x. Lavrinovich A.A.
  1. The practical recommendations for the experimental investigation of the interaction of the electron beams with non-homogeneous semiconductor structures of circular and rectangular cross-section have been established. New information about some features of interaction of electron beam with bounded non-homogeneous semiconductor structures which are used in up-to-date radiophysics and plasma microwave electronics (for designing experimental samples of plasma amplifiers and generators) has been obtained. Rusanov A.F., Yakovenko V.M.
  2. The propagation of electromagnetic waves in periodic artificial media has been investigated. The influence of the drift of carriers and charged particle beams on the dispersion properties of the waves, their instabilities and non-linear interaction in bounded superconductor superlattice has been theoretically studied. The theory of resonance scattering of the electromagnetic waves on periodic structures which are formed by the modulation of the relief as well as the optical properties of the media has been developed. The scientific novelty of research is to determine physical properties of bounded semiconductor periodic media placed into external electric field and metallic superlattices. The work has been devoted to nanoelectronics. The fundamental physical properties of periodic layered structures which can be used as new materials for technical mastering new frequency ranges have been studied.  The obtained results describe resonance effects in metal nanostrucures and can be used for designing of optical devices. Rusanov A.F., Nikitin O.Yu.

2006

  1. The calculation technique of the characteristics for the waveguide-coaxial resonator of the millimeter wavelength band. The numerical calculations that suppots the experimental investigations were carried out. Bilous R.I., Motornenko A.P.
  2. The interaction of electron beams with metal waveguide of rectangular cross-section partially filled by the plasma, namely, by two semiconductor plates arranged along the wide walls in an external magnetic field has been studied. The features of interaction of electron beams with electromagnetic waves in magnetoactive semiconductor waveguiding structures have been found. The numerical analysis shows that electron beam effectively interact with electric fields in magnetoactive semiconductor structures. The two types of space-charge waves can be unstable in structures under study. If frequencies of van Kampen waves and cyclotronic waves coincide with the eigenmodes frequency of plasma, the increments are top. Rusanov A.F., Yakovenko V.M.
  3. The possibility of using the transition radiation of an electron bunch to generate nonstationary anharmonic pulses in free space and in a dispersive medium is demonstrated. It is shown that the transition radiation of the bunch gives rise to an infinite train of nonstationary anharmonic pulses described by solutions to the Klein–Gordon equation. The polarization of the resulting field at its leading edge appears to be different from the field polarization at the interface. The leading edge becomes steeper with time. It is shown that the bunch density longitudinal distribution and the parameters of the dispersive medium can be determined from the values of the fields and their derivatives near the leading edge of the resulting signal. Averkov Yu.O.
  4. The instabilities in the fine-layered nano-periodic structure created by the semiconductor layers with different types of conductivity were s The actuality of the study of these instabilities connected with the fact that at this time the compact solid-state devices for the generation of electromagnetic waves are lacking in the millimeter and submillimeter ranges. It is shown that a two-component solid-state plasma allows us to get to the instability for the existing materials. This is connected with the drift wave of a new type found in the paper.. This wave occurs in the periodic structure formed by layers of n- and p-semiconductors, and extends at an angle to the boundary layers. For mentioned above wavelengths range the such structure can be created with help of nanotechnology for fine-layered material. Bulgakov A.A, Shramkova O.V.
  5. A linear temperature dependence of the microwave conductivity of optimally doped HTSC YBa2Cu3O7-d film was obtained at low temperatures (<10 K) with developed in IRE NASU original measurement technique based on WGM sapphire resonators. The dependence may indicate a presence of pairing scenario of charge carriers with d-wave symmetry. The result is consistent with the results of foreign researchers. Experimental determination of the symmetry of the order parameter in HTSC is an important element in the fundamental problem of constructing a microscopic theory of high-temperature superconductivity. Barannik A.A., Cherpak N.T.
  6. The study results of the excitation of dielectric resonators on whispering mode showed that their spectral and energy characteristics substantinally depend on the type of excitation and electrodynamic characteristics of a radiation source.
In order to study the electrical properties of liquids with high energy losses of the microwave field, a highly sensitive measuring cell was developed on the basis of DRWG .The results of the experimental studies have shown that this cell can be used to detect the distinctive features of liquids, whose properties do not differ significantly. For example, investigated and identified characteristics of different types of water (distilled, sea and mineralised ). Based on paragraph A, such analogs, which refer to the study of the resonators, excited by the main type of oscillations, do exist. Based on paragraph  B, the relevant analogs do not exist, because the design of the measuring cell is unique. The above mentioned results can be directly used for a design of a microwave equipment based in DR.he results specified  in paragraph A allow to achieve more accurately the required output characteristics or to improve them, taking into consideration the characteristics of the DR excitation source. Paragraph B allows to create a highly-sensitive  dielectrometer of  millimiter waves based on DR in order to study a wide variety of liquids, including liquids with high losses of microwave energy. Kirichenko A.Y., Kogut A.E., Solodovnyk V.A., Kutuzov V.V.
  1. An approach was developed to determine the electrophysical parameters of substances based on the experimentally defined spectral and energy characteristics of inhomogeneous quasi-optical resonators. Wideband resonance methods for determining the permittivity of dielectrics including liquids and gases, and surface resistances of conductors and superconductors were justified. It was shown and partially realized the possibility of determining the electrophysical parameters of material from which a resonator or a portion thereof is made. The developed approach for the determination of electrophysical parameters of substances has no analogues in Ukraine. Knowledge of electrophysical parameters of substances is necessary in almost all fields of science, medicine and industry. Developed and realized wideband resonance method for determining the electrophysical parameters of materials using inhomogeneous quasi-optical resonators can be used in the development of devices for measuring the permittivities of substances including gases and liquids with both small and large losses as well as the surface resistances of conductors and superconductors. On the quasi-optical dielectrometer, which contains a measuring cell in form of a two-layer radial cylindrical resonator, the authors obtained a declarative patent of Ukraine. The scientific significance of the results is that the potential of radiophysical complex (theoretical and experimental) approach to the analysis of complex electrodynamic structures is far from exhausted and has the prospect of further using. The obtained knowledge, and developed and realized physical tool for studying of the "whispering gallery" resonator are a prerequisite for the develop of new resonator structures that can be used for basic research in the millimeter wave range. Barannik A.A., Kirichenko A.Ya., Kogut A.E., Prokopenko Yu.V., Smirnova T.A., Filippov Yu.F., Cherpak N.T.

2007

  1. As part of the research based on the Maxwell's equations, the electrodynamic problem about eigenmodes of radially three-layer cylindrical and spherical dielectric resonators was solved for the first time. The computer programs allowing to determine the eigenfrequencies and Q-factors of resonators as well as the field structure and the energy density distribution of their eigenmodes were compiled and debugged. Numerical experiments on the studying of radially three-layer dielectric resonators in which the layers are made of different materials including liquids both large and small losses were carried out. The influence of the middle layer with different parameters on the spectral and energy characteristics of resonators has been analyzed. It was proposed to use the resonators to determine the complex permittivity of materials. Filippov Yu.F., Prokopenko Yu.V., Smirnova T.A., Shipilova I.A., Suvorova O.A.
  2. The new variety of the dielectric resonator with the auxiliary disc were carried out. In this resonator the effective tuning of the characteristics of the high-Q microwave oscillations was obtained. Kirichenko A.Yu., Martynyuk S.P. ,Моторненко О.П. Skuratovskiy I.G.
  3. The frequency dependencies of the magnetic and TEM oscillations in the waveguide-coaxial resonator were investigated and the comparison between their oscillations and the oscillations of the waveguide-dielectric resonator was made. Bilous R.I., Martynyuk S.P., Motornenko A.P., Skuratovskiy I.G.
  4. The laboratory setup for the growing of the single crystals BiSb (bismuth-antimony alloy) were made. The setup for the manufacturing of the point contact SHF detectors on the basis of the BiSb crystals and the detection section for the elektromegnetic radiation in the 2-and 1-millimeter wavelengths was completed. The amplitude and noise characteristics of the detectors for the 8-mm wavelength range on the basis of the BiSb metal-semimetal point contactswere studied, current-voltage characteristics and the breakdown phenomena in the metal-semimetal point contacts were found to determine the power capability that is dissipated with the prototype, the volt-watt characteristic for the detectors of the SHF range based on the BiSb semimetal (120-270 GHz) is defined. Plaksіy V.T.
  5. A new nonresonant radio-physical method for studying of complex conductivity of high-temperature superconductors was justified and developed. The developed method allows studying of high-temperature superconductors in extreme temperature conditions, which is essential to study the properties of high-temperature superconductors at the critical temperature and above it, i.e. in a normal state. The first results on the fluctuation conductivity investigation at a temperature from 115 K and below were obtained. The method may be useful for the study of other condensed matter, complex conductivity or permeability of which varies under the influence of external factors Gubin A.I., Lavrinovich A.A, Cherpak N.T.
  6. The highly sensitive measuring cell of dielectrometer to measure the permittivity of different types of water based on the results of studies of electromagnetic characteristics of half-disk dielectric resonator with the whispering gallery modes was created. Experimental investigation of water with different content of salt impurities (distillate, sea water, tap) was carried out. It was identified by distinctive peculiarities of the investigated samples. Experimental investigation of the anisotropic dielectric sphere located in the far field of the illuminator was carried out. The peculiarities of the excitation of the resonator at the higher oscillation modes of the whispering gallery were determined. The resonance scattering of a beam of millimeter waves on a sphere whose diameter is comparable to the wavelength of the radiation was investigated. The effect of converting electromagnetic characteristics of the quarterspherical dielectric resonator by the coupling slot was studied. It was obtained the mutual synchronization and power added three Gunn diodes in quarterspherical dielectric resonator when it used in solid-state power combiner. Kogut A.E.
  7. The resonance interaction of the Rayleigh wave and a surface helicon, which propagate along an interface plane of a vacuum-solid-state plasma in the presence of high magnetic field, is investigated. The obtained results give the possibility of excitation of a surface sound with the aid of a magnetic dipole that is placed near the interface. The expression for the decrement of the collisionless relaxation of the Rayleigh wave into bulk helicons is derived. It has been shown that at low temperature this relaxation mechanism dominates over usual collision relaxation of a surface sound. Averkov Yu.O., Bass F.G., Yakovenko V.M.
  8. The instability of the infinitely thin electron beam that moves above the interface of vacuum-left-handed material has been investigated theoretically. The absolute instability is shown to occur due to the interaction between the beam and the backward surface waves that propagate along the interface. The equation for the coupled surface waves and the space charge waves in the beam as well as the expressions for the instability increments has been derived. Averkov Yu.O., Yakovenko V.M.
  9. A nonlinear theory of interaction (three wave processes) in layered periodic structures with semiconductor layers in an external constant magnetic field, a theory of electromagnetic wave propagation in bounded layered structures were constructed. The new types of surface waves were found and the waveguide between two layered periodic structures was considered. The possibility of the controlling with the waves properties in these structures with the help of an external magnetic field was shown. Bulgakov A.A., Kostyleva O.V., Shramkova O.V., Kononenko V.K., Olhovsky E.A.

2008

  1. The excitation of the electrostatic waves above the surface of the layered superconductor by means of the electron bunch has been theoretically investigated. The dispersion relation of the surface waves for an arbitrary value of the tilt angle of the layers with respect to the crystal surface at any propagation direction of the surface wave has been found. It is shown that the hydrodynamic instability has absolute character and it is important for designing of generators in the optical frequency range. Averkov Yu.O., Yakovenko V.M.
  2. Excitation of surface polaritons by an infinitely narrow electron beam propagating in the vacuum gap between a metal-like medium and an artificial dielectric with a negative permeability is studied theoretically. A dispersion relation is derived for the waves excited by the beam for an arbitrary thickness of the gap. The possibility of the emergence of absolute instability is demonstrated for an infinitely narrow vacuum gap, and the corresponding increments are calculated with allowance for small dissipative losses. Averkov Yu.O., Kats A.V., Yakovenko V.M.
  3. The penetration of the potential barrier at the interface between a conducting medium and a dielectric (vacuum) has been theoretically investigated. It has been shown that in the case where a surface polariton propagates along the interface, the electron energy changes at its collision with the interface. The probability of radiation (absorption) of the surface wave energy quantum by an electron at its reflection and penetration the interface has been determined. The dependence of the coefficients of the induced radiation (absorption) on the electron energy and the surface wave frequency has been built. Beletskii N.N., Khankina S.I., Yakovenko V.M.
  4. The eigenmodes of dielectric sphere were investigated in the presence of permittivity spatial dispersion. It is shown that its effect leads to a new type of surface oscillations near the absorption bands. Filippov Yu.F., Yakovenko V.M.
  5. An electrodynamic analysis of semi-cylindrical dielectric resonator with a cylindrical inhomogeneity in the field of axially-homogeneous "whispering gallery" mode was carried out. The effect of such a little dielectric or metallic inhomogeneity on the spectral and field characteristics of resonator with TMms 0 mode was studied. It is shown that the inhomogeneity shifts the eigenfrequency of resonator and leads to additional energy losses of TMm s 0 It was noted that the main contribution to the perturbation of the mode field is made by the fields of TMm' s' 0 eigenmodes of cylindrical inhomogeneity for which the azimuthal index m' << m. It was proposed to use a semi-cylindrical dielectric resonator with a cylindrical inhomogeneity for measuring the electrophysical parameters of substances, which occupy small volumes, as well as for the mechanical tuning of the frequency of auto-oscillator that is stabilized high-Q semi-cylindrical dielectric resonator by the introduction of a metal pin in the region of the maximum field of "whispering gallery" mode. Prokopenko Yu.V., Filippov Yu.F., Shipilova I.A.
  6. The characteristic equation of the cylindrical three layers semiconductor resonator with the ideally conductive end surfaces and the expressions for the field components of its natural oscillations were obtained. Filippov Yu. F., Smirnova T.A.
  7. The possibility of using a radially two-layer spherical dielectric resonator as a sensor to determine the complex permittivity of environment was studied. It is shown that the sensitivity of a change of the eigenfrequency of "whispering gallery" mode resonator to a change of the permittivity of environment is determined by a radial thickness of outer layer. High sensitivity is provided by a small thickness of this layer. The outer layer of the resonator is made of a substance for which the real part of permittivity is much higher than the similar parameters of the material of inner layer and the outer environment. In this case, the resonators' Q factor, which is sufficient for the measurement, is provided by a radial dimension of outer layer that is determined by the losses of electromagnetic energy of the resonator eigenmode in the external environment. In the long-wavelength part of the millimeter range the resonator with inner layer out of quartz and outer layer out of polikor was studied at immersing it into different environment in liquid or gaseous phase. Kirichenko A.Ya., Prokopenko Yu.V., Suvorova O.A., Filippov Yu.F.
  8. Special analysis technique of multicomponent solutions in which water is a dominant component has been developed  by using a simultaneous measurement of DR permettivity at different frequencies. Its efficiency is best shown at an analysis of dry wines  samlessamples. Kirichenko A.Y., Golubnichaya G.V.
  1. The technique of the analysis of the limited periodic structures was worked out. A theoretical study of the dispersion properties, fields and energy flows in the structures composed of layers with periodic dielectrics, semiconductors and ferrites was carried out. Bulgakov A.A., Kostyleva O.V., Shramkova O.V.
  2. The investigation of electrical properties of liquids in the millimeter wavelength range with the use of high-Q dielectric resonators with whispering gallery modes was continued. The measuring cell based on a layered hemispherical dielectric resonator was created. The possibility of its using for the investigation of the properties of a number of liquids on the basis of different alcohols was determined. Kirichenko A.Y., Kogut A.E.
  3. It was found that the residual surface resistance (i.e. resistance at T ®0) in superconductors YBa2Cu3O7-d varies as a function of frequency ω3/2 for films and single crystals, which suggests the intrinsic nature of this effect. These results were obtained using a new measurement technique of impedance properties investigation of high-Tc superconductors, proposed and developed by the authors on the basis of WGM sapphire resonators. Cherpak N.T., Barannik A.A., Bunyaev S.A.
  4. The problem of the power summation of the transition radiation, which is created witn a flow of electrons in the case of direct or alternating electric current, which flows through the media interface, was studied. It is shown that at a constant current, in a uniform random distribution of the electrons, the total power of the transition radiation is different from zero and is proportional to the total number of electrons N, which cross the border section at a time. If there is alternating current the space-time correlation of the electron distribution exists, as a result of which the coherent summation of radiation fields of individual electrons happens. Yurchenko B.
  5. The peculiarities investigation of the resonance oscillations in the new waveguide-dielectric structure offered in IRE NASU was carried out. The eigen frequencies and eigen Q-factors for T-oscillations of the waveguide-dielectric resonator were calculated and measured. The parameters influence of the electrodynamics structure on the electric characteristics of the resonator was shown. Білоус Р.І., Martynyuk S.P.,Моторненко О.П. Skuratovskiy I.G.
  6. The first phase oscillations of the longitudinal sound propagating in an antiferromagnet (weak ferromagnet) iron borate FeBO3 (in the H field) were studied. The nature of the phase modulation of the longitudinal sound, most likely was connected with the piezo-magnetic properties of the iron borate. (On the transverse sound in the same conditions the oscillations of the sound amplitude take place). Theory of phase effect is currently being developed. The composite acoustic resonator Fabry-Perot interferometer in an antiferromagnetic FeBO3 was implemented and studied. Tarakanov V.V.
  7. Numerical and experimental results of the investigations of the impedance of the avalanche-transit time diodes (ATD) for the 8-mm wavelength range, the dependences of the impedance of the ATD as a function of the normalized amplitude of the first harmonic of the current for the pn-junction, and frequency of the active and reactive conductances ATD have been obtained. Also the frequency and amplitude fluctuations of the electromagnetic oscillator of the 8 mm wavelength range were studied. A numerical evaluation of modulation noise depending on the parameters of the ATD was carried out, the results of the spectral densities of the amplitude and frequency noise as a function of the frequency analysis were obtained. In addition, the volt-watt characteristics of the detectors of the millimeter wavelength range wave on the basis of the point metal-semimetal BiSb contact were studied. Plaksiy T.

2009

  1. The effect of a potential barrier on the mechanisms of instabilities of plasma oscillations under its interaction with the flow of the charged particles intersecting the boundary of the conducting medium has been studied. The various forms of the potential barrier (wall, square barrier, d-like barrier) existing at the interface of the media with different electromagnetic properties have been considered. The probabilities of processes of radiation and absorption of surface plasmons by a charged particle have been found. The increments (decrements) of plasma oscillations have been found. Their dependence on parameters such as the particle energy, plasmon energy, the length of the potential barrier has been established. Khankina S.I., Yakovenko V.M.
  2. The theory of forced oscillations in the isotropic spherical dielectric resonator that is excited by an azimuthally periodic current flowing in a circular orbit located outside/inside or on the surface of the ball in its equatorial plane was developed. It is shown that in a resonator there are H and E modes with the polar index . At that, the H modes have the polar and azimuthal indices, the sums of which have odd values. The sums  of E modes have zero or even values. As a result, in a resonator there are not the azimuthal TEn n s modes and azimuthally-homogeneous TEn 0 s modes with paired polar indices . In the case of polar odd indices  in a resonator there are not also the azimuthally-homogeneous TMn 0 s In a resonator the azimuthal TMn n s modes are always excited. Since the azimuthal index is uniquely determined by the periodicity of electric current, the polar and radial indices of excited modes are uniquely determined by the solution of the characteristic equation for the natural oscillations of resonator. In result of the frequency selection in the resonator the one mode with indices  is only excited on the frequency of current radiation: . As a result an amplitude resonance occurs when the frequency of current radiation aspire to the eigenfrequency of resonator. The field distribution of excited mode is formed by the superposition of the fields of radiation source and eigenmode of resonator at the frequency, where there is a resonance, and of close modes to it at the excitation frequency. The excitation efficiency of the sphere depends on the interaction distance between the current and the surface of spherical dielectric resonator.
The obtained results have no analogues in Ukraine and abroad. It should be noted that the excitation spherical dielectric resonators in the optical range are considered in the United States. In Ukraine, the excitation of "whispering gallery" modes in such resonators in the millimeter wavelength range is only considered in the O.Ya. Usikov Institute for Radiophysics and Electronics of NASU. The obtained results allow to approach consciously to an excitation of oscillations in spherical dielectric resonators or its design modifications in the millimeter wavelength range. Such resonators can be used in various microwave devices such as generators, filters and devices for determination of the electrophysical parameters of substances. Prokopenko Yu.V., Filippov Yu.F., Yakovenko V.M.
  1. The instability of an infinite thin electron beam propagating in vacuum over the surface of an isotropic nongyrotropic crystal is investigated. The possibilities of exciting additional longitudinal waves and polarization waves are analyzed. The dispersion laws of exciton–beam coupled waves are obtained. It is demonstrated that the interaction of the beam with the additional bulk longitudinal wave and the surface polarization wave leads to the appearance of the absolute instability. It should also be noted that the surface nature of exciton–beam coupled waves leads to a weaker scattering of these waves from optical phonons as compared to an intense scattering of exciton polaritons in the bulk of the sample. This facilitates the possibility of experimentally revealing these waves, which have dispersion characteristics that make it possible to determine the binding energy and the effective radius of Wannier–Mott excitons. Averkov Yu.O., Bass F.G., Yakovenko V.M.
  2. The transition radiation of an electron beam traversing the wire screen has been theoretically investigated. The beam has the form of the periodical series of discrete bunches and moves along the normal to the screen. Each of the bunches by itself has the form of the segment of the charged filament which is directed normal to the beam velocity. The wire screen is located in vacuum and has the form of a one-dimensional array of parallel metal wires. Two different mutual arrangements of the bunches and the wires, namely, the perpendicular and the parallel arrangements have been considered. The spectral energy density, the directional diagram, and the numerical estimations of the radiation power have been obtained. It has been demonstrated that the transition radiation is the series of harmonics. The harmonic frequencies are multiple of the reverse spatial period of the modulated beam. The directional diagram has maximum along the wires for the non-relativistic coherent bunches. Averkov Yu.O., Yakovenko V.M.
  3. Surface electromagnetic waves propagating along an anisotropically conducting interface of two different dielectrics have been theoretically investigated. The flat surface of the interface contains a one-dimensional array of thin metal wires. It was assumed that both the lattice constant of the array and the diameter of the wires are far less than the lengths of the surface waves. It has been shown that the surface electromagnetic waves may propagate along the interface at frequencies which are far lower than the plasma frequency of a metal, and the electric field of the waves is always perpendicular to the wires in any propagation directions. The existence conditions, dispersion relations, and energy fluxes of the surface waves have been derived. It has been demonstrated that the surface electromagnetic waves can be excited by means of the transition radiation and beam instability effects. The effect of the dissipative loss on the dispersion relations of the waves has been taken into account. Averkov Yu.O., Yakovenko V.M.
  4. Investigated multicomponent aqueous solutions in the form of must and made with them their table wines from white sorts of grapes. It is established that the dielectric constant of wine at 8 mm wavelength range allows with high reliability to predict the quality of wine made from it by using dielectric constant of the source material (must). Pair correlation of the dielectric constant of the must and sugar content in the corresponding wine amounts to 0.72, which is higher than the corresponding pair correlations between the mass concentrations of sugar or pH of the starting materials and residual sugar in the wine. This method of valuation of initial  materials allows to increase the quality of wines made from them. A method is proposed and tested Kirichenko A. Ya., Golubnichy G. V., in cooperation with specialists of the national Institute of vine and wine "Magarach" UAAS Yalta Kirichenko A. Ya., Golubnichaya G. V.
  5. The calculation and experimental investihations of avalanche-transit time diodes in order to use them in the microwave technique of the millimeter wavelengths were carried out. The microwave radiation detectors based on semimetal Bi1-x Sbx (x = 0,1) in the frequency range (120-270) GHz at T = 300 K were experimentally investigated. The volt-watt sensitivity of the microwave radiation detectors based on the metal-semimetal BiSb contacts in depending on the geometry of the contacts was definited and the expression for the volt-watt sensitivity as a function of the parameters BiSb was obtained. Plaksiy V.T.
  6. The magnetic oscillations of the longitudinal sound phase and amplitude in the acoustic Fabry-Perot resonator vade of the antiferromagnetic FeBO3 have been studied. Tarakanov V.V.
  7. Major studies have focused on the study of resonance absorption of electromagnetic energy of the waveguide mode H10 the different types of water (tap water, artesian, with a depth of 721 meters, melt water (which were taken from different parts of the city)), which fills the capillaries in the capillary-waveguide resonator. The possibility of using of capillary-waveguide resonator for the assessment of water quality by identifying of microimpurities in its composition is experimentally investigated. The resonance absorption of the energy of water in capillary-waveguide resonator at frequencies 63 ÷ 72 GHz is investigated. The high sensitivity of frequency, Q-factor and the depth of the resonance absorption of energy in the presence of low concentrations of microimpurities in the water are demonstrated. The approach that has been developed, as well as the results can be interesting for operational monitoring of drinking water. Particular interest is the high sensitivity of the method to trace contaminants which enables to use it not only to control the tap water, but also water solutions of chemical and biological agents, including the stage of their production. Krivenko Е.V.
  8. A computer program for the fast calculation of the electromagnetic waves in the millimeter and submillimeter wavelength band for the photonic crystals made from the metal wires and dielectric plates was developed. The result speeds upis the development of the multilayer photonic crystals millimeter and submillimeter waves. The result has been applied to the development of the improved two-layer polarizers millimeter and submillimeter waves. The two-layer polarizers millimeter and submillimeter waves with quadratic increase in the degree of the polarization in the directions of the transmission and (on special frequencies) reflection have been devepoled. The development is a perspective for measuring of the polarization of the cosmic microwave relict radiation in the radio astronomy for the study of the the conception of the Universe which is one of the main directions of the physical achievements of the international scientific community. Yurchenko V.B.
  9. The electromagnetic characteristics of the dielectric resonator as hemiball with hemispherical cavity filled with various liquids (water, butanol, methanol, benzene, toluene, glycerol) were investigated. The regularities of changes of the spectral and energy characteristics of the test cavity on the level of filling the cavity by liquids and their values of the dielectric constant were determined. It is shown that these patterns should be used to identify the liquids examined. Kutuzov V.V., Maksimchuk I.G., Nosatyuk S.O., Solodovnyk V.A.
  10. The investigation of forced whispering gallery modes, excited in the dielectric resonators be the concentrated sources of electromagnetic radiation was continued. By scanning fields forced oscillation dielectric resonators found that in contrast to their own oscillation distribution fields substantially depends on the excitation conditions and methods. Kogut A. E.
  11. A theory of propagation of electromagnetic waves in fine-layered periodic structures created layers of semiconductors, dielectrics and ferrites, located in an external magnetic field was constructed. It is shown that with the help of an external magnetic field the structures properties can be controlled. The transmission and reflection coefficients of the electromagnetic waves as a function of the fine-layered structures were analytically and numerically obtained. First theory was constructed and the existence conditions of the electromagnetic waves whose phase velocity is equal to the velocity of the electrons in semiconductors in an external electric field were found. Bulgakov A.A., Kostyleva O.V., Shramkova O.V.
  12. The temperature dependence of the microwave surface resistance and surface reactance of new superconducting single crystal Ba (Fe1-xCox) 2As2 was obtained for the first time. These results were obtained using the proposed and developed by the authors technique of measuring impedance properties of new superconductors such as Fe-pnictides Barannik A.A., Cherpak N.T., Torokhtii K.I.
  13. The investigations of the peculiarities of the resonance electromagnetic oscillations of the magnetic types in the waveguide-dielectric resonator were continued. The eigen frequencies and eigen Q-factors for these oscillations in the waveguide-coaxial resonator were computed. The experimental investigations were carried out for the microwave band. The computed results and the experimental data were agreed. Білоус Р.І., Martynyuk S.P.,Моторненко О.П. Skuratovskiy I.G.

2010

  1. The spectra of the electromagnetic eigenmodes in bounded plasma-like media (films, low-dimensional systems, the structures like metal-dielectric-semiconductor etc.) are in terahertz frequency range. The instabilities of the eigenmodes can develop under intersection of the media with the directed flows of charged particles. The transition radiation effect is the basis for the amplification of the surface oscillations. During this effect the particles fields excite the radiation fields at the interface. In this case the process of transformation of the particles kinetic energy into the energy of the surface oscillation occurs. Apparently, the inverse process of transformation of the surface oscillations energy into the particles energy must occur. The instability arises in the case where the radiation process dominates the absorption process. Since the fields conversion occurs at the interface, the surface plasmons are the most perspective for generation of instabilities because they are “bound” to the surface. The interaction of the charge particles with the field of the surface plasmons can be described by different ways. If the amplitude and the phase of the field of the surface plasmon (vector-potential) are given, then the interaction is considered as the process of electrons scattering on the surface plasmon potential. In this case the amplitude change of the surface plasmon potential, i.e. decrement or increment of oscillations, is derived from the Maxwell equations, Schrödinger equation and boundary conditions. On the other hand, the interaction of the charged particles with the field of the surface oscillations can be considered as the process of random collisions of fermions (electrons) and bosons (surface plasmons). During the process the change of surface plasmons number can be described by the kinetic equation. The both approaches are used in studies of influence of the potential barrier at the interface on occurrence instabilities of the surface plasmons due to the transition radiation of the beam’s particles. It has been shown that the mechanism of interaction of the charged particles and surface plasmons displays itself differently depending on the relation between the charged particle energy, height of the potential barrier and the plasmon energy . At low height of the potential barrier (,) there are regions of decay and growth of the amplitude of the surface plasmon which defined by the value of . The threshold value of  at which the instability occurs has been obtained. It has been shown that the presence of the potential barrier extends the range of the values of the particle energy which result in amplification of the oscillations. However, the investigations with the use of kinetic equation for the surface plasmons lead to the conclusion that the potential barrier decreases the increment value. The method of finding of the matrix elements which appear in the kinetic equation and determine the value of increment (decrement) has been proposed. In the case of infinite potential barrier the occurrence of the instability of the surface oscillations depends on the form of the boundary conditions for the electron wave functions. If the wave function at the interface equals zero, then the surface plasmon decays. Khankina S.I., Yakovenko V.M.
  2. The theoretical analysis of the kinetic instability of a finite-temperature electron beam propagating in a vacuum above the flat dielectric surface in the case where the surface contains a one-dimensional array of perfectly conducting parallel thin wires has been performed. It was assumed that both the lattice constant of the array and the diameter of the wires are far less than the length of the surface waves. It has been shown that the oblique surface electromagnetic waves are excited due to the instability. The expression for the instability increment (decrement) has been derived. It has been demonstrated that the maximum instability increment corresponds to the oblique surface waves propagating at a certain angle with respect to the wires. Averkov Yu.O., Yakovenko V.M.
The excitation of well-localized oblique surface waves above the surface of a dielectric with a one-dimensional array of perfectly conducting wires is studied theoretically using the method of attenuated total reflection (ATR). It is assumed that the distance between the wires and their diameter are much smaller than the surface wavelength. The frequencies of excited surface waves are much lower than the plasma frequency of the metal, and their electric field is orthogonal to the wires. It is shown that such surface waves can be excited with the help of a homogeneous TM wave as well as with the help of a homogeneous wave with an electric field polarized perpendicularly to the wires. It is found that in the course of excitation of oblique waves, the incident TM wave is partly polarized into a wave of the TE type. Our results remain valid in the case of excitation of oblique surface waves by the ATR method in Kretschmann’s geometry, in which the gap between the prism and the wires is filled with a dielectric, and the domain under the wires is vacuum. This makes it possible to use thin dielectric plates with arrays of metal wires deposited on them as waveguide structures for oblique surface waves. We have also demonstrated that oblique surface waves can be excited by a homogeneous wave with the electric field polarized perpendicularly to the wires. Averkov Yu.O., Yakovenko V.M.
  1. The natural oscillations theory in an isotropic semiconductor sphere was developed, in which spectral and energy characteristics of antimonide-indium resonator with a radius of 1 cm were studied. It is shown that in it, except for volumetric microwave oscillations a surface oscillation occurs. In the middle of the sphere, the amplitude of surface oscillation decays exponentially along the radius from the resonator surface. For large values of the polar index, the surface oscillation becomes to a plasmon that exists on a semiconductor plane. Volumetric oscillations that exist at frequencies above the plasma frequency have a dense spectrum. These oscillations are different with values of the radial index. With the increase in the radial index the eigenfrequencies of modes increase, and the quality factor of the resonator decreases sharply. The eigenfrequency of the resonator with a lower mode (radial index is equal to one) with polar index less than 30 has close to the plasma frequency. The eigenfrequency of the resonator increases with increasing polar index more than 30. In semiconductor spherical resonator there is only one surface oscillation at frequencies below the plasma frequency. The eigenfrequency and the quality factor of resonator increases with increasing polar index. For large values of the polar index the frequency of surface mode approaches asymptotically to the frequency of plasmon, which exists on a boundary between the semiconductor and vacuum. This is because the curvature of spherical surface does not influence the oscillation parameters with large polar mode index. The quality factor of the semiconductor sphere has an extreme of maximum.
The development of the theory of natural oscillations in gyrotropic cylindrical resonator that is placed in an axial static magnetic field and immersed in a vacuum environment is started. The characteristic equation of such resonator and the field components expressions of its eigenmodes were obtained. It is shown the solutions of the characteristic equation describe both "whispering gallery" modes and surface oscillations. A qualitative analysis of magnetized cylindrical semiconductor resonator with quasi-azimuth-homogeneous modes (axial wave number is not very different from zero) was made. The existence regions of the quasi-azimuth-homogeneous oscillations of magnetic type in antimonide-indium resonator had been determined. The influence of the magnetic field leads to the depending of the resonator eigenfrequencies on its value and direction. In strong magnetic fields the resonator eigenfrequency varies slightly. When a magnetic field is absence, the eigenfrequencies of resonator with modes, which have large values of azimuthal indices, approach to the frequency of the surface plasmon that exists on a boundary between the semiconductor and vacuum. The results allow conscious approach to the use of cylindrical and spherical semiconductor resonators or their structural modifications. These resonators can be used in various microwave devices, such as generators, filters, millimeter-wave devices under controlled and in devices for determination the electrophysical parameters of semiconductors. Prokopenko Yu.V., Filippov Yu.F.
  1. Numerical and experimental investigations of the frequency and amplitude characteristics of the ATD generators mm wavelength range, as well as volt-watt characteristics of the SHF detectors based on the film of the bismuth-antimony alloys were carried out. The substantiation of the single crystal growth of the bismuth-antimony alloys by zone recrystallization was obtained. Plaksiy T.
  2. The nature of mitigation of acoustic modes in the weak ferromagnetic was studied in detail. The mitigation is a reduction of the resonance frequencies of acoustic modes of the resonator made of weakly ferromagnetic FeDQ3 with a magnetic field decreasing. The standard Sіvі model [M.N.Seavay, Solid State Communication 10. 219-223 (1972) gives only one mode mitigating - the "magnetic", but this is inconsistent with the experimental results. Our approach uses the piezomagnetic addition to the energy of the weak ferromagnet. It is found that the calculation of the magnetization m of the piezomagnetic component in the sound wave (mz║q║D, where q is the sound wave vector, D - Dzyaloshinsky axial vector) gives the connection between two sound modes through the z- component of the vector m, which is present in the "soft" and in the hard sound mode. Thus, the separation of the modes in their rigidity, which takes place in the traditional approach, taking into account the piezomagnetic effect. This result makes it possible to more strictly than before, to explain the mitigation of the rigidity of the acoustic mode in a weak field, which is described in the article (Tarakanov VV, Khizhnyi VI, FNT 22, pp. 752-757, 1996). It is shown that piezomagnetism can really give the new physical results and it is not just a small addition to the standard magnetostriction as previously thought. Tarakanov V.V.
  3. The distributions of fields of forced whispering gallery modes(WGM) excited in the 8-mm wavelength range in the half-disk dielectric resonators (DRs) by local coupler were investigated by scanning of the receiving antenna in the form of an open end of the metal waveguide. It was shown that in contrast to the own modes of such resonators the forced modes field distribution depends on the WGM excitation conditions. The significant influence on the value of the Q-factor of half-disk DR can have radiative energy losses. Their value is determined not only by the parameters of the resonator and the excitation conditions of the WGM in them. Through the use of DR with WGM, a new design of the measuring cell dielectrometer to study electrical properties of liquids in mm wavelength range was proposed. Provided the use of a hollow hemispherical DR, the inner cavity is used to partially fill the test liquid. Investigations of a number of different samples with high energy losses have shown the high sensitivity and resolution of the measurements. Kogut A.E.
  4. A new design of the measuring cell for dielectrometry of The cell is an open dielectric resonator as half ball made of Teflon with semispherical cavity. Earlier perturbation of the resonance field carried out by the external resonator caustic immersion it in liquid. While the change in resonant frequency and Q-factor was controlled. At present investigation the liquid slowly poured into the cavity and used its influence on the internal cavity caustic. The comparative analysis of the results for different liquids was carried out. It is determined that such resonators are suitable for the study of the dielectric properties of liquids on whispering gallery modes in the frequency range 32-37 GHz. The following liquids - methanol, butanol, toluene, benzene and water were investigated. Kogut A.E., Kirichenko A.Y., Solodovnik V.A., Kutuzov V.V., Maximchuk I.G., Nosatiuk S.O.
  5. Unlike standard (indirect) methods of determining dielectric permeability of liquids: a waveguide, resonator and measurement in free space (and their numerous variants, we propose a direct method of determining the refractive index of liquids in the millimeter range of electromagnetic waves. The study of his opportunities was continued this year The developed method uses a direct measurement of the length extending in a fluid wave by the metal vibrating string. For  this purpose, in this period investigated the opportunities measure the dielectric permittivity of a multicomponent weak aqueous solutions  dry and  table wines and their source materials in the form of must (initial material from which wine is made)were investigated. A parallel study of the refractive index of the wort and wine showed an unexpected opportunity to establish a more accurate prediction of wine quality research just, than other previously used techniques. The correlation coefficient of the mass concentration of residual sugar in the wine with the sugar concentration in the original must (r=0,65-0,63) is relatively smaller than a corresponding correlation coefficient of permittivity of the must  (r=0.96-0,72). It was also found that the dielectric constant of wine correlates with the following results: concentrations of ethyl alcohol, the concentration of calcium ions, sulphate and viscosity. The value of the dielectric permittivity measured by the proposed method in the millimeter range, is correlated with the value of dielectric permittivity, obtained by the resonator method in three-centimeter range of colleagues from Kharkiv national University.
The use of the proposed method to clarify the differences in the indexes of refraction of the mineral waters of the Kharkiv region, extracted from sources Rogan, Paradise-Yelenovka, Shestakova and Shatilovka boundary showed the boundary  possibilities of this method. However, the differences of the coefficients of refraction of water from these water sources and water Kharkiv was clearly established by the nature of the change of refractive index under conditions of temperature change. These differences become weaker over time, when just taken from the tap water stand for a while. Kirichenko A. Ya., Golubnichaya G. V.
  1. The study of interaction of electron fluxes with new materials and structures has been carried out. A.F. Rusanov held internships at the National Synchrotron Radiation Research Center, Taiwan. During the internship the investigations of wake fields generated electron flow in the electron accelerator "Tayvanske Photon Source" (Taiwan Photon Source) have been done. The simulation of the insanities of the electron beam and other collective effects has been performed. The results were presented by three papers at the First International Conference on Accelerator Physics (1st International Particle Accelerator Conference) Kyoto (Japan) 23-28 May. Rusanov A.F.
  2. The technique of processing the experimental results of measurement of the temperature dependence of the surface impedance of small sized superconductors by means of the WGM sapphire resonators was developed.The temperature dependence of the penetration depth, density of superconducting electronic component and density of quasi-particle component for a new superconducting single crystal Fe-pnictide, namely superconductor Ba (Fe1-xCox)2As2 was obtained from the results of measurements in the millimeter wave band. The results show that the superconductor is not a BCS-type superconductor. According to the analysis of the temperature dependence of the penetration depth and the density of superconducting electronic component, symmetry of the order parameter can be s + / s- or nodal (nodal), that is, with the nodes of the gap function. Preliminary analysis of the temperature dependence of the quasi-particle liquid density shows no coherence peak, which does not coincide with those of other authors. This feature requires further investigation. The study of electromagnetic characteristics of sapphire QDR (i.e. WGM resonator) with HTS films as CEP and the radial gap with the measured superconducting sample inside of it was continued. Barannik A.A., Cherpak N.T.
The theoretical analysis and simulation of the method of studying microwave response of HTS and related materials by measuring the reflectance of the sample during the propagation of the wave through the waveguide corner section with the sample under test were carried out at grazing angles of incidence. The expediency of using the corner section with smooth transitions, in which the height of the waveguide varies according to the hyperbolic tangent, was shown. The conditions for increasing the sensitivity of the method were determined and the optimal conditions were chosen based on the relationship between the height of the sample placing relative to  the waveguide, the angle of incidence and the linear dimensions of the test sample. Gubin A.I., Lavrinovich A.A. The HTS film-based transmission line of planar waveguide type with nonlinear properties was created. The characteristic power of the signal was found experimentally, at which the nonlinear dependence of the propagation of the input signal was observed. The ability to control non-linearity was demonstrated experimentally by passing DC through the line. Gubin A.I., Lavrinovich A.A., Cherpak N.T.
  1. It was shown that the slow waves can propagate with a velocity 3000 times lower than the speed of light in the periodic structure consisting of the dielectric and semiconductor layers in a magnetic field. This is possible for the frequencies near the plasma resonance. The thickness of the layers of the structure must be equal to several hundred nanometers. The properties of the fine-layered periodic structure dielectric-semiconductor in a magnetic field were considered. It is shown that such structure has the properties of a biaxial crystal. Properties of this material can be controlled by varying the magnetic field. In addition, the theory of reflection of the electromagnetic waves of such structure located on a metal surface is constracted. The analysis of the epsiloidal features of the reflected signal as a function of the magnetic field and the layers sizez was carried out. The properties of the contact between the periodic structure and the semiconductor layer were considered. The transmission of the electromagnetic waves through a structure was analyzed. The transmittance peak in the overlap region of the bandgap of the periodic structure and negative permittivity of the semiconductor layer was found. Also the surface waves that propagate along the contact between the periodic structure and the semiconductor layer were investigated. The effect of the external magnetic field on the electrodynamic properties of the investigated structure was studied. The processes of the waves generating with the combination frequencies of the nonlinear dielectric and semiconductor layers in the case when two flat waves fall on the layer were investigated. The influence of the geometrical and physical parameters of the structure on the intensity of the reflected wave with a combination frequency was analyzed. The influence of an external magnetic field on the properties of the natural waves of the periodic and quasi-periodic waveguides formed by layers of semiconductor and dielectric was considered. The dispersion dependences and the field distribution for the limited structures were obtained. The transmission spectra of the TE waves through the ferrite-semiconductor layered periodic structure were investigated. The dependence of the frequency as a function of the thickness of the layers, as well as the influence of dissipative processes in the layers and the external magnetic field on the transmittance of the electromagnetic wave was studied. Bulgakov O.O, Shramkova O.V., Kostyleva O.V.
  2. By the controlled light the frequency selective switches of the quasi-optical beams of the electromagnetic waves based on the photonic crystals (PC) of the millimeter range (in particular, which work at frequencies f = 75 - 100 GHz) with increased sensitivity and operation speed was proposed. Numerical simulation and optimization of their parameterswas carried out. The testing of the principal possibility of the operation of the switch with the light source such as the flash was carried out together with the staff of the Department of Experimental Physics of the National University of Ireland, Maynooth (Ireland) on the basis of our experimental base. Testing was performed for the structure sample from four plates of the own GaAs (with a resistivity of 0.1 Mohm * cm) without the use of the additional PC patterns for the radiation in the frequency range f = 75 - 110 GHz. The comparison of the obtained data and the simulation results demonstrates the feasibility of the switches, which, in the case of the using of the optimum PC structure can provide the beam switching with a modulation depth of 30 dB under the influence of light pulses with a peak power up to 300 W / cm2. Yurchenko V.
  3. We investigated the electrodynamic system which consisting of autogenerator on Gunn diode, stabilized by partially shielded dielectric resonator, and determined its sensitivity to the introduction into the resonator of small disturbances by using vibrations of whispering gallery (WG). For this in the cavity at the area of the caustic WG field at a distance of 2 mm from the border of the dielectric screen located capillary outer diameter of 5 mm and 1.1 mm internal. Camera of the generator through the diaphragm 7,2 × 1,0 mm 2 was connected with a resonator. Changes of the frequency and slope of electronic tuning depending on the fluid which filling the capillary been study. Required for the measurement of fluid volume was about 10-2сm3. It is experimentally shown a relationship between the value of the imaginary part of the dielectric constant of the absorbing medium, which partially fills the quasi-optical resonator with a slope of electronic tuning frequency stabilized oscillator. This allowed us to propose a new approach to measuring the imaginary part of the dielectric constant of the medium, partially filling a quasi-optical resonator, which is not based on the use of amplitude measurements cavity loss or Q, and based on the measurement of the slope of electronic tuning generator stabilized cavity. Studies carried out using half-disk cavity partially shielded, but the results and the calculated ratio may be used to analyze other types of high-Q resonators, which are used in high vibration modes, and the duty ratio of the absorbing medium is small. Using frequency dielectric measurements to estimate parameters of the environment, instead of combined frequency - for the real part and amplitude - for the imaginary part of the permittivity, can simplify the construction dielectrometer, at the same time to achieve higher accuracy. When creating dielectrometer important solution to the problem of mechanical tuning frequency of generators, stabilized by dielectric resonator. It is necessary to combine the reference and measurement frequencies generators at a point calibration. One of solution - introducing into the resonator a heterogeneity in the form of metallic or a dielectric pin. Studied the effect of depth of the pin from metal or dielectric, upon the natural frequency is partially shielded half-disk quasi-optical dielectric resonator (CHEKDR) and frequency-stabilized they Gunn diode. It is shown that increasing depth of immersion leads to a reduction in the frequency of generation, for the oscillations of WH and the bouncing ball (BB). When the metal pin tuning range of oscillator frequency for these modes is approximately 110 MHz and 40 MHz, accordingly, while for the fluoroplastic pin - about 30 MHz and 10 MHz.
On location of the characteristics of the radio emission satellites and their connection with the meteorological and refractometric parameters of the troposphere is studies. The possibility of monitoring the supply of water in the clouds from the received radiation satellites is shown. The high-altitude dependence of refractive indices and their gradients in different seasons is experimentally studied. The possibility of using a global navigation system for determining the refractive index of the troposphere investigated. The relationship between the measured height and the state of the troposphere is shown. Method for estimating the amount of sources reflecting, their location and heights of troposphere refraction on the spectra of the amplitude fluctuations of the received signal systems, GPS & GLN is proposed. Krivenko Е.V.
  1. The peculiarities investigations of the basic resonance structure of the waveguide-dielectric type have been continued. The calculations of the eigen frequencies and eigen Q- factors for the fundamental mode of the magnetic type in the waveguide-dielectric resonator (WDR) of the millimeter wavelength band were carried out. On the bases of these calculations the WDR has been made for the frequencies 28-38 GHz and its characteristics have been measured. The comparison between the experimental values of the frequencies and Q-factors and computed data was shown the good agreement for the frequencies and satisfied - for the Q-factors. The new peculiarities for the resonance oscillations of the T- and H modes in the waveguide-coaxial resonator (WCR) have been found through comparison. The frequencies band for the T- And H- modes in the centimeter wavelength band for the chosen dielectric have been determined through the computed and experimental investigations. The existence band of the oscillations in the WCR depending on resonator parameters has been determined. The possibility of using of the simplified method of calculation of the eigen frequencies of the fundamental H111 mode in the resonators of the centimeter wavelength band for the small inner diameter of the coaxial has been shown. The efficiency of excitation of oscillations for T and H type depending on the choice of instrument for their local excitation has been studied. Bilous R.I., Martynyuk S.P., Motornenko A.P., Skuratovskiy I.G., Khazov O.I.

2011

  1. The study of electronic processes which take place at the surface of the conducting media is of interest to up-to-date microelectronics. From this standpoint the investigations of electron states at the interface between the plasma-like medium and dielectric (vacuum) in the presence of a potential barrier are important. The expressions for increments (decrements) of instability of surface plasma oscillations in the case where the potential barrier is step-like rectangular and d-shaped form have been derived and analyzed. The non-linear interaction of the electron wave with electromagnetic waves (longitudinal and transversal) in semiconductors has been considered. It has been shown that the electron transits into the state with greater or less energy as the result of its scattering on electromagnetic waves (decay instability). During the transition to the lower level the amplitudes of the electromagnetic field and the wave function, which describe the electron behavior with identical increment, increase. As the result of transition of the electron to the high-energy level the increasing is absent. The Vavilov-Cherenkov effect has been studied from the standpoint of the decay instability, namely, this effect can be explained as the scattering process of the electron on the electromagnetic fields created by this electron. The non-linear effects in the waveguide and the resonator with conducting walls filled by layered superconductors have been studied. It has been shown that the frequencies and amplitudes of the Josephson plasma oscillations (waves) are changed. Khankina S.I., Yakovenko V.M.
  2. The Tamm-type surface electronic states at the boundary of the one-dimensional structure with periodically potential profile have been theoretically studied under the condition that the δ-shaped quantum well is at this boundary. The properties of surface electronic states in such a structure have been compared with Tamm electronic states in the absence of a quantum well at the lattice boundary and with electronic states localized near the δ-shaped potential well deep in the lattice. In particular, it has been shown that the existence of the δ-shaped potential well at the lattice boundary facilitates a significant increase in the degree of localization of Tamm-type surface electronic states and makes possible the appearance of these states at arbitrarily small heights of lattice potential barriers. Averkov Yu.O., Yakovenko V.M.
  3. In this paper, we present the theoretical analysis of surface electromagnetic states at the interface between a photonic crystal and a plasma-like medium. It was assumed that an elementary cell of the photonic crystal is composed of two different non-magnetic dielectrics. The change of frequencies of surface electromagnetic states with the configuration of the elementary cell has been studied. We have shown that at certain parameters of the elementary cell a number of surface electromagnetic states can exist. These states differ in frequencies and their electromagnetic field localization in the photonic crystal and in the plasma-like medium. The possibility of existence of surface electromagnetic states in metal-photonic crystal structures with layers of and  has been demonstrated. These structures are widely used for up-to-date applications of silicon nanophotonics. Averkov Yu.O., Beletskii N.N., Yakovenko V.M..
  4. The frequency dependence of the transmission coefficient of the electromagnetic wave passing through an artificial plasma-like medium (PLM) on the amount of metal has been theoretically and experimentally studied. The quartz substrates coated by thin metal strips (100-150 nm) with different periods are used as the PLM. It is experimentally shown that the plasma frequency of the PLM increases with the number of metal strips. The influence of the PLM on the transmission spectrum of the spatially periodic structure (the dielectric PC) has been experimentally investigated. The researches are carried out in 22-40 GHz frequency range. It has been demonstrated that the transmission peak (the so-called Tamm’s peak) occurs in the forbidden zone of the PC. This peak implies the occurrence of the surface oscillation at the PC-PLM interface. Averkov Yu.O., Kharchenko A.A.
  5. The electrodynamic analysis of cylindrical dielectric resonator with forced "whispering gallery" oscillations had been carried out when they are excited by an azimuthal-periodic current source. The theory of forced oscillations in cylindrical dielectric resonators (CDRs) has continued to develop. The computer program for displaying the field distribution of forced modes in resonator when an electric current pass in the axial direction of resonator axis both in inside and outside was designed and debugged. We have explained the need for and developed an auto-oscillatory system based on a quasi-optical CDR with "whispering gallery" modes. In this system the flight time of electron between the end walls of resonator is less than the half-period (or commensurate with an odd number of half periods) of its eigenmode. A multi-stream azimuthal-periodic electron beam was formed that allowed "whispering gallery" modes with different axial and radial indices to be excited. The high-Q CDR with conducting end walls was excited by a relativistic electron beam. The electromagnetic energy was extracted from the resonator by exciting a slit radiator situated at the rear end wall in maximum of HE36 1 l mode field localization (l= 0, 1, 2). A microwave radiation from the studied system in the 7…9 mm wavelength range was detected.
Thus, we have formulated the principles of constructing microwave radiation sources with high-Q quasi-optical CDRs, in which azimuthal-periodic electron beams excite "whispering gallery" modes. It should be noted that when the electromagnetic field structure is retained there is a linear relationship between the wavelength of CDR eigenmode and its diameter; if the field structure is violated, the wavelength of CDR eigenmode is inversely proportional to the azimuthal mode index. Thus, by decreasing the resonator radius and/or using the "whispering gallery" modes of higher order with respect to the azimuthal index, it is possible to implement the proposed or modified system with acceptable geometry parameters in the terahertz frequency range. Dormidontov A.V., Prokopenko Yu.V., Filippov Yu.F.
  1. The optimal speed for the growing of the single crystals of the bismuth-antimony alloys using the method of the zone recrystallization has been calculated. It was shown that the maximum crystal growth rate did not exceed 0.5 mm/h. We investigated the volt-watt characteristics of the detectors for the SHF range based on the bismuth-antimony films. Expressions for the sensitivity of the detectors depending on the electrophysical parameters of the material were obtained. It has been shown that the sensitivity can be controlled with the variation of the polarity and magnitude of the applied voltage. Plaksiy V.T.
  2. Investigations of the electrical properties of liquids, which showed that in the millimeter wavelength range is advisable to use a resonant measuring cell. These cells can serve as proposed dielectric resonators with half ball cavity excited to whispering gallery modes. When the perturbation of resonant systems test liquid is achieved by changing the resonant frequencies of tens to hundreds of megahertz, depending on the sample liquid. Thus they can be identified. The properties of liquids like; methanol, butanol, toluene, benzene, water. The priority in terms of providing the best sensitivity measurement modes are E-type. Kogut A.E., Kirichenko A.Y., Solodovnik V.A., Kutuzov V.V., Maximchuk I.G., Nosatiuk S.O.
  3. Proposed and developed a new rapid method for the direct measurement of the refractive index of liquids in the millimeter band of the electromagnetic spectrum. The method allows to measure the length of a wave propagating in the liquid. The proposal is based on the use of interference between two waves propagating in the liquid, one of which is reflected by the metal vibrating strings in fluid. The tests of the method, which showed it possible at researching samples of multicomponent aqueous solutions, such as wines and drinking water. The capillary waveguide resonance in fluids with a high level of absorption of electromagnetic waves in the shortwave band of the millimeter range (4 mm) discovered. By using this resonance studied permittivity of aqueous solutions. The methods used do not have their analogues in the near or far abroad. These studies have shown the possibility of using the proposed methods for research liquids used in pharmacology, biology and medicine. Kirichenko A.Y., Golubnichy G.V., Krivenko Е.V.
  4. The peculiarities investigations of the basic resonance structure of the waveguide-dielectric type have been continued. With a view to the investigation of the possibility of the practical use of the waveguide-dielectric resonator the experimental investigations of the eigen frequencies and Q-factors dependences for the fundamental H111 mode as a function of the short-circular plunger position have been studied. The calculations by our method have been made for the chosen parameters of the resonator. The calculations and experiments have been carried out for the centimeter and millimeter frequency bands:
As a result, it was shown that the waveguide-dielectric resonators with the short-circuit plunger can be computed and designed for the centimeter and millimeter wavelength band using the proposed method. It was shown that the eigen frequencies can be varied over a wide band according to calculations. In this case the value of the eigen Q-factors of the H-mode in the waveguide-dielectric resonator were lower then computed, it must be considered in practice. Bilous R.I., Martynyuk S.P., Motornenko A.P., Skuratovskiy I.G., Khazov O.I.
  1. A correlation between the quasiparticle scattering rate, the London depth and surface impedance for an arbitrary value of the mentioned rate in the Drude formula was generalized. The technique of the quasiparticle scattering rate determination in unconventional superconductors based on the experimental measurement results of the superconductors surface impedance dependending on temperature was elaborated. An estimation in a superconducting single crystal Ba (Fe1-xCox)2As2 was obtained. Cherpak N.T., Barannik A.A.
The A modified coplanar waveguide transmission line based on epitaxial HTS film with nonlinear impedance was made jointly with the staff of Peter Gruenberg Institute, Forschungszentrum Juelich, Germany to continue studying peculiarities of such transmission lines with nonlinearity controlled by direct current. Gubin A.I., Lavrinovich A.A.
  1. The theoretically investigation of the peculiarities of the transmission spectra of the ferrite-dielectric periodic structure, in which we introduced an additional "defective" semiconductor layer has been carried out. The presence of such layer leads to additional transmission peak. The peak can be located in the forbidden or permitted zone. It depends on the placement of the "defective" layer in the periodic structure and what kind of layers surround it. The given investigation showed that the peak transmission can occur at frequencies where the bandgap of the periodic structure and a region of the negative permittivity of the semiconductor is overlaped. It was shown that the existence of the peak was due to the peculiarities of the interference processes in the periodic structure. The possibility of the controlling of the peak frequency using an external magnetic field was demonstrated. In addition, the peculiarities of the fields division and energy flows were considred. This allowed to explain the physical features connected with the existence of the transmission peak in the bandgap, the presence of the oscillations of the energy in the periodic structure. Bulgakov A.A., Kostyleva O.V.
  2. In a series of papers the theory of the electrodynamics for the waveguide processes in fine-layered periodic structure of the semiconductor-dielectric in a magnetic field was developed. Fine-layered structure is a structure whose period is much smaller than the length of the electromagnetic wave propagating in the structure. It has been shown that such structure is a optical biaxial crystal having permittivity components that depend on as the physical parameters of the layers as the layers thickness and the external magnetic field. In the expressions for the components of the permittivity tensor of the fine-layered structure appear a number of the features associated with the fact that the tensor components go to infinity or vanish. This leads to the specific properties in the electrodynamic characteristics of the fine-layered structure. It should be noted that a slight change in the external magnetic field significantly changes the parameters of the polarization ellipse. This allows us to control parameters of the structure, as well as to measure the value of the magnetic field.
It is shown that in a limited structure two types of surface waves are propagated. One of them is propagated at the frequencies where the components of the dielectric tensor have a negative value. That is, the propagation of these waves occurs at the frequencies below the plasma frequency. The second type of surface wave occurs at the frequencies higher than the plasma frequency. Its existence is connected with the peculiarities of the biaxial structure tensor (Dyakonov waves). It has been shown in the paper about the reflection and transmission of light through a limited fine-layered structure that the dependence of the reflection and transmission coefficients as a function of the angle of incidence, the frequency and the external magnetic field allows to determine the transmission band and stopband, as well to analyze the properties of layers and the change of the magnetic field allows to "manage "with the optical properties of the structure. It should be noted and the phenomenon of conical refraction.. Because of the anisotropy of the fine-layered structure a number of the characteristic frequencies and magnetic field values that determine the areas of the possible realization of the conical refraction phenomena in the concrete structure is appeared. Artificial structures make it possible to solve the problem of the presence of biaxial crystals with a given geometry and electrodynamic parameters. Their application can find in the areas of the possible use of the conical refraction: in laser technology, in radiophysics and optics, as well as the application area can expand through the effective management of the electrodynamic and optical parameters of this structure. Bulgakov A.A., Fedorin I.V.
  1. The one-dimensional photonic crystals of the millimeter-wave with the resonance inserts in the form of the wafers of the silicon, gallium arsenide or cadmium telurida films on the plates of the fused silica with a quality factor Q> 1000, suitable for the creation of the quasi-sensitive switches W range that can be controlled by the light pulses, which are emitted by an array of light-emitting diodes were theoretically and experimentally studied. There are partial counterparts abroad that use other materials, work in other frequency bands and require high-power pulsed lasers. The structures proposed in the work, increase the sensitivity of such devices in W band of the the millimeter-wave. The result is speed up the development of new devices in the millimeter and submillimeter wavelengths band based on photonic crystals, which use the semiconductor materials. The simulation results are used for the experimental testing of such devices. Yurchenko V.B.
  2. The occurrence possibility of the magnetic modulated structure in a iron borate plate with a modulation vector in the direction normal to the plate, which coincides with the axis of the third order C. (axis OZ) was considered. The mechanism that leads to the binding of the transverse acoustic branches in the weak ferromagnet was investigated. Such link between the different transverse branches (modes) can be realized because of the piezo-magnetic effect. Tarakanov V.V.
  3. It has been studied the distribution of electromagnetic fields and the characteristics of different types of quasi-optical resonators to determine the possibility of their use as cell of dielektrometra; stabilizing properties of quasi-high-Q resonators for frequency solid-state Gunn oscillator. There were also differences in the dielectric characteristics studied pure and polluted air and water in the millimeter and optical waves to create a radio physical methods of monitoring. We studied the fluctuations of the whispering gallery in the open cylindrical resonator excited by a capacitive gap. Study the distribution of the field, determined dependence the Q, self resonant frequency of the position of the excitation gap. It was shown that the use of such systems for measuring the humidity of the gas transported through the pipeline. There was also the possibility of a multifrequency mode oscillator stabilized by two resonators. It was found that the stabilization of Gunn oscillator with two resonators becomes possible to induce the two-frequency oscillation mode. The frequency spacing, as well as the influence of the applied voltage to the Gunn diode to the frequency characteristics of the resonators is studied. Krivenko Е.V.

2012

  1. Electromagnetic fundamental oscillations in layered finite-sized superconductors, which fill a rectangular resonator, are investigated theoretically. The spectra of ordinary and non-ordinary eigenmodes are obtained. The nonlinear effect of decrease in frequency of the non-ordinary eigenmodes is analyzed and the generation of the third harmonics of oscillations is studied. The nonlinearity of the system is due to the nonlinear dependence of the Josephson current density across the superconducting layers on interlayer phase difference of the order parameter. We study the Josephson plasma waves running along a waveguide filled by a layered superconductor, and the nonlinear effects accompanying the propagation of these waves. In addition, a phenomenon of terahertz waves stopping in waveguides caused by the combined effect of the nonlinearity and damping is predicted. Khankina S.I., Yakovenko V.M.
  2. The surface electromagnetic states (SEMS) in a structure which is an electromagnetic analog of a semi-infinite one-dimensional lattice with a -shaped quantum well have been theoretically investigated. This structure consists of plasma-like medium (PLM) which is separated from a photonic crystal (PC) by a thin defective layer. The PC consists of a periodic sequence of dielectric and plasma-like layers. It is assumed that the width of the PC dielectric layers is considerably greater the width of the plasma-like layers as well as the width of the defective layer. This gives the possibility to consider the plasma-like layers as the analog of the -shaped quantum barriers (potential wells) in the SEMS problems and to use the Kronig–Penney method to derive equations describing the In these frameworks it has been shown that:
  • the presence of a defective layer at the PLM-PC interface leads to the appearance new SEMS, decreasing the frequencies of the defectless SEMS, and promotes the increasing of the localization degree of the SEMS in the vicinity of the interface.
  • in the case where the defective layer is the plasma-like one, the sertain optimal plasma frequency (corresponding to the highest localization degree) exists. It is established that the SEMS become delocalized in the PC region when the plasma frequency of the plasma-like defective layer excceds sertain critical value. Averkov Yu.O., Yakovenko V.M.
  1. The theoretical analysis of transmission spectrums of a finite width photonic crystal bordering on a wired metamaterial with different effective material parameters has been performed. The photonic crystal is composed of a finite number of elementary cells. It was assumed that the elementary cell is consisted of two different non-magnetic dielectrics. The wired metamaterial is in the form of two-dimensional periodic array of metal wires placed into a dielectric matrix. Tamm states in the structure of the photonic crystal / metal wires have been detected experimentally. the influence of temperature and number of metal wires on the transmission spectrum of the structure have been investigated experimentally and theoretically. The shift of the transmission peak of the photonic crystal in the constant magnetic field has been predicted. The shift is caused by the dependence of the Voigt permittivity on the constant magnetic field. Averkov Yu.O., Beletskii N.N., Tarapov S.I., Kharchenko A.A., Yakovenko V.M.
  2. In this paper, the theoretical analysis of oblique surface Josephson plasma waves (oblique SJPWs) that propagate along an interface between a dielectric and layered superconductor is first presented. The case where the superconductor layers are perpendicular to the interface is considered. The oblique SJPWs are the surface electromagnetic waves propagating in the interface plane at an arbitrary angle with respect to the superconductor layers. The electromagnetic field of the waves is the superposition of ordinary and extraordinary surface electromagnetic waves. The dispersion equation of the oblique SJPWs has been derived. This equation is the most general dispersion equation of the SJPWs in the case under study. The problem of excitation of oblique SJPWs by means of the attenuated total reflection method is solved. It has been established that the process of the excitation of oblique SJPWs is accompanied by onset of an additional reflected wave in the prism with a polarization orthogonal to the polarization of the incident wave. It has been found that the reflection coefficient of the exciting wave in the prism can vanish for some optimal parameters of the structure. It is found that in the case where a one-dimensional layers of ideal conducting wires parallel to the -axis of the superconductor is placed on the bottom of the prism, the polarizations of the incident (ordinary) and reflected wave in the prism are the same. The dependence of the propagation angles of the SJPWs on the angles of incidence of the exciting wave in the prism has been calculated. This dependence shows that there are threshold values of the propagation angles of the SJPWs exist in certain frequency range. The values of the angles are defined by finite values of the dielectric permittivity of the prism. Averkov Yu.O.
  3. The effects of changes in temperature and the air permittivity of environment to changes of the eigenfrequencies and Q-factors of CDR with "whispering gallery" modes were determined. An attempt to separate the effects of these factors on the spectral and energy characteristics of Teflon and sapphire resonators for a millimeter wavelength range has been made for the first time. The different behavior of CDR eigenfrequencies and the stability of Q-factors were found out when the temperature is varied from –60 to +60°C and the permittivity of air is changed within from 1 to 1.00002 for Teflon and from 1 to 1.02 for sapphire resonators. The sensitivities of changes of the eigenparameters of Teflon (= 3.9 cm,  = 0.7 cm) and sapphire ( = 2.83 cm and  = 0.24 cm) resonators to the changes the permittivity and temperature of the ambient air space have been determined in the 35...47 GHz frequency range. On the one hand, it is established that for the detection of air permittivity changes (refractive index) at the temperature of 20 °C through the changes of resonator eigenfrequencies it is necessary to measure the ambient temperature with accurate up to 10-5 °C that allows to take into account the shifts of resonator eigenfrequencies due to the thermal expansion of its volume. The necessary accuracy of frequency measuring is on the order of 10 Hz. On the other hand, it is shown the proposed quasi-optical CDR can be used as a temperature sensor that ensures a precision on a level of 10-4 °C provided that the resonance frequencies are determined to within 100 Hz. The acceptable variation of the refractive index of ambient air does not exceed 0.03 -units or 1 -unit using Teflon or sapphire resonator respectively. However, sapphire resonator allows to provide the accuracy of atmosphere temperature measurements up to 10-5 C when the resonance frequencies are measured with an accuracy of 10 Hz, since at the natural fluctuations of the air refractive index within 0.05 -units the shifts of its eigenfrequencies are implemented within 6 Hz. It is justified that using solutions of the inverse electrodynamic problem and taking into account corrections to the spectral characteristics of a quasi-optical resonator related to the linear thermal expansion of the dielectric and/or variation of the permittivity of surrounding, it is possible to determine the temperature and/or permittivity of ambient air by measuring the resonance frequencies to within 10 Hz, which is acceptable to the modern instrumentation. The method for determining the air refractive index using investigated quasi-optical CDRs as a temperature sensor and a measuring cell of resonator refractometer was developed. It is proved the accuracy of determining the air refractive index is provided at the level of 10-2 -units.
Together with the staff of the IPENMA of NSC "KhIPT" of NASU we have developed the self-consistent nonlinear theory of the electromagnetic radiation excitation of millimeter wavelength by the high-current relativistic azimuthal-periodic electron beam in a cylindrical cavity with a dielectric rod. Nonlinear numerical analysis was made. Prokopenko Yu.V., Dormidontov A.V.
  1. The possibility of the modulated magnetic phase formation in the iron borate FeBO3 in the direction of the main axis of the crystal was studied. It is shown that the modulated phase can be induced with the standing longitudinal sound wave in the plate-resonator by the piezomagnetic effect. The nature of the magnetic oscillation of the longitudinal sound in iron borate crystal was investigated. Tarakanov V,V.
  2. An experimental study of the electrical properties of fluids in the 8-mm wavelength by the resonator method using dielectric resonators with whispering gallery modes was continued. The regularities of the influence of different liquids on the formation of the main electrodynamic characteristics of dielectric resonators are shown. The characteristics of the generation of oscillations of the whispering gallery in partially shielded inhomogeneous dielectric resonators in the mm wavelength range are study. Kogut A.E., Krivenko V. Kirichenko A.Y., Lutsenko V.I.
  3. We investigated the characteristics of hemispheric dielectric resonators with concentric cavity filled with different alcohol-water solutions to ascertain the possibility of their use in the construction of a dielectrometer. To reduce the influence of the coupling element in the experiment used a distributed connection cavity with dielectric waveguides by turning on a "per pass." The change of the resonant frequency and Q-factor are the main indicators of informative parameters of alcohol-water solutions of different concentrations (in increments of 10%). It is found that the proposed measuring cell has high resolution with respect to alcohol-water solutions. Kogut E, Kutuzov V.V., Maksimchuk I.G., Nosatyuk S.O., Solodovnyk V.A.
  4. The research focused on the study of characteristics of electromagnetic characteristics of quasi-optical dielectric waveguide resonators and perturbed by inhomogeneities in the form of strongly and weakly absorbing media. As a perturbing field of the resonator media used capillary liquid and a dielectric or metal pins. Experimentally studied the effect of irregularities in the spectral characteristics of quasi-optical partially screened dielectric resonators and resonator of capillary-type waveguide in the millimeter wavelength range, which can be the basis for the creation of methods to measure the dielectric characteristics of both strong and weak absorbing media. Based on the results of written thesis work "Electrodynamic characteristics of quasioptical dielectric and waveguide resonators with discontinuities", the protection of which will take place on December 20, 2012. Kirichenko A.Y., Krivenko A.V.
  5. In 2012, continued research aimed at the improvement of new methods for studying the electromagnetic properties of the fluids in the millimeter wavelength range electromagnetic waves. With this purpose, we used our method of vibrating string to study the electrical properties of multicomponent aqueous solutions. Samples were  wines that are produced at the Institute of vine and wine "Magarach". Studies revealed that in contrast to the results obtained by the research staff of the Institute of Radioengineering and electronics, Russian Academy of Sciences, the sugar content in wines to a greater extent affects their electrical properties than ethanol. If the research of these solutions in the IRE of Russia was carried out using a waveguide methods and criterion for changing the electrical characteristics of wine is the damping factor propagating through the waveguide waves in our studies are directly modifying the real part of the refractive index.
Further development of the study of electrodynamics disc quasi-optical dielectric resonators. Attention was drawn to the need to study the quality and efficiency of the excitation plate dielectric resonator. Such a resonator according to numerous statements would have been of interest for use in research environments that surround it. However, the data use it for this purpose in the literature are absent. No data on the quality factor of these resonators and the effectiveness of their arousal. In our studies in the millimeter range of the amplitude-frequency characteristics of plate-type resonators made of policor and fused quartz, it is found that in dielectric resonators, made of plates of 0.5 mm thickness the whispering gallery oscillations are not excited. The quality of plate resonators with the number of plates  greater than 3 (the thickness some individual plates are 0.5 mm ) is reduced by an order of magnitude compared with the disk resonators from the same plates without air gap. The maximum quality factor in the plate resonator can be achieved when the magnitude of the electromagnetic energy stored in the dielectric material is about 50% of the total energy exciting the resonator. Kirichenko A. Ya., Golubnichaya G. V.
  1. The systematic studies of the characteristics of the resonator in a wide frequency range, including the millimeter wavelength band were carried out. The resonator model was a piece of circular copper waveguide with dielectric inserts inside it. The moving short-circuit plunger located in one of the sections of the evanescent the waveguide was used for the smooth mechanical tuning of the resonant frequency. The eigen frequencies and Q-factors of the fundamental asymmetric magnetic oscillation in the waveguide-dielectric resonator (WDR) were numerically calculated and measured. As a result of made investigations the imperfection of the base resonator with short-circuit plunger has been determined, namely, it is necessary to make a more accurate of the compound parts of the resonator to reduce or eliminate the effect of the gap between the plunger and the wall of the evanescent waveguide on the Q-factor oscillation, especially in the millimeter wavelength band. A new design of the waveguide-dielectric resonator with a resonant short-circuit plunger has been proposed and the preliminary studies of the eigen frequencies and Q-factors of this resonator have been carried out. It is shown that due to the proposed resonant short-circuit plunger can significantly improve the Q-factor of fundamental mode in the WDR. Bilous R.I., Martynyuk S.P., Motornenko A.P., Skuratovskiy I.G., Khazov O.I.
  2. The relationship between the effective and intrinsic (bulk) surface impedance was obtained for superconducting thin films under condition when the microwave field at the surface of the film has an opposite direction relative to the field at the opposite surface of the film. The relationship expands options in the location of the thin film in a microwave cavity and thereby extends the capabilities of the studying superconducting thin films Cherpak N.T.
The temperature dependence of the effective microwave impedance of the thin film superconducting FeSexTe1-x was obtained experimentally. Other composites of this family of superconductors were studied abroad. The experimental data allow determining the main characteristics of the FeSexTe1-x electronic system Barannik A.A. A mm-wave band stable oscillator based on a small-sized semiconductor module was created. The analogues in Ukraine are absent. The oscillator was created to conduct studying of microwave properties of superconductors and bioliquids using WGM resonator technique developed in IRE NASU. Gubin A.I.
  1. Theoretical studies of the electrodynamic properties of the thin film periodic structure, when the length of the electromagnetic wave that propagates in the sample is much smaller than the period (so-called small-layered structure) were carried out. The structure which consists of the layers of the dielectric and semiconductor which has frequency dispersion is analyzed. It is assumed that it is placed in a constant external magnetic field. In addition, the properties of the plastic material can be controlled by physical and geometrical structure parameters. Small-layered periodic structure in a magnetic field is an optically biaxial crystal with effective components of the permittivity tensor, which depend on the physical parameters of layers and the thickness of the layers and the magnetic field. The dependences of the permeability tensor elements of the fine-layered structure on the frequency and magnetic field were studied. The analytical expressions for the characteristic frequencies and magnetic fields in which the tensor components are converted to zero or infinity were obtained.
In contrast to the dielectric layered structure and periodic semiconductor structure without a magnetic field in the band spectrum of the small-layered structure of the semiconductor-dielectric in a magnetic field there are two permitted areas for the investigation surface waves. The influence of dissipative processes on the characteristics of the surface waves was numerically analyzed. It is shown that taking into account the damping leads to the change of the surface wave’s parameters. The elliptic of the electromagnetic field for the reflection from the small-layered structure which is located on the metal substrate was studied too. It is shown that the Bragg resonance condition for the structure under consideration has a number of interesting features. So, at some frequencies and magnetic fields values the wavenumbers of the small-layered structure become imaginary and there is the total internal reflection. At the same time the incident electromagnetic wave is reflected completely from the structure boundary and the reflection coefficient has a maximum value. It is shown that the position of the Brewster angle, as well as areas of transmission and non- transmission can be effectively controlled by the magnetic field and the layers thickness. Bulgakov A.A., Fedorin I.V.
  1. The theory for the layered periodic structure consists of two different dielectric layerswas considered. In one of the dielectrics are allowed excitons. The analytical and numerical investigation of the dispersion equation for a limited sample was carried out. The solution for the surface waves that exist in the forbidden band for the propagation of the electromagnetic wave was considered. It is found that on each structure surface there are independent from one another the surface waves. The investigation of the peculiarity of the surface waves have been investigated and explained by analyzing of the imaginary energy flux. Baibak V.V., Bulgakov A.A.
  2. The properties of the slow surface wave in the periodic thin-layered magnetoactive structure of the dielectric-semiconductor were considered. It is shown that the moderating ratio may be of about 103. It was found that the dependence of the phase velocity of the wave and the relative attenuation as a function of the layers thickness of the structure have the symmetry properties relative to their values for the structure with equal layer thicknesses. Bulgakov A., Kononenko V.K.
  3. According to the plan of SRW "Centaur-5" (p. 7) a theory was developed and experimental studies (conducted by the National University of Ireland, Maynooth) of the new effect of the light switching of the quasi-optical beams of the millimeter waves via Bragg resonant structures with a photosensitive layer of a semiconductor, which have significantly increased sensitivity to light control pulses compared to other known structures of this type were carried out. On the basis of the developed theory a new more sensitive and precise method for the measuring of the dielectric materials parameters which have the significant high-frequency loss (including liquid materials, aqueous solution and other substances) was suggested. It is achieved by using the special reflection mode of the high-frequency waves from resonator structures with the test material provided a special structures optimization. Yurchenko V.B.
  4. The dynamics of nanomechanical oscillator in the presence of the external periodic force in the regime close to the resonance was studied. Oscillator interacts with a two-level system, which is also excited on the frequency, close to its eigenfrequency. The interaction of the both systems with the thermal bath was taken into account, which leads to damping and decoherence of the quantum-mechanical state of the system. It is shown that for a specific ratio between the period of oscillations and times of damping and decoherence of the two-level system a strongly nonlinear response of the oscillator may be observed, for the specific amplitude of external force there are several states of oscillation with different amplitudes. This effect is related to the interaction between the oscillator and the two-level system and it is shown that there exist up to five states with different amplitudes, two of them are unstable and three are stable. In the framework of self-adjusted interaction the amplitudes were found, and for the points, close to bifurcation point, the rate of jumps between the stable states was found. Maizelis Z.A.
  5. The research focused on the study of characteristics of electromagnetic characteristics of quasi-optical dielectric waveguide resonators and perturbing discontinuities in the form of strongly and weakly absorbing media. As a perturbing field of the resonator media used capillary liquid and a dielectric or metal pins. Experimentally studied the effect of irregularities in the spectral characteristics of quasi-optical partially screened dielectric resonators and resonator waveguide capillary-type millimeter wavelength range, which can be the basis for the creation of methods to measure the dielectric characteristics of both strong and weak absorbing media.
Based on the results of written thesis work "Electrodynamic characteristics of quasioptical dielectric and waveguide resonators with discontinuities ", the protection of which will take place on December 20, 2012. Kirichenko A.Ya., Krivenko Е.V.

2013

  1. The energy losses of a charged particle moving along a spiral path were theoretically and numerically determined for the excitation of the natural oscillations in the cylinder, which represents a dielectric or plasma-like medium. A static magnetic field is directed along the axis of a cylinder. It is shown the motion of a particle along a spiral leads to both Cherenkov and gyrosynchrotron radiation that expands the excitation possibility of oscillations in the cylinder. The conditions for the appearance of gyrosynchrotron radiation were found. The electromagnetic fields of oscillations were determined and it is shown their dependencies on the radius of cylinder depend essentially on a frequency interval. We have studied the energy losses of a charged particle for the excitation of natural (potential) oscillations in a nanotube. A nanotube is a cylinder surface that represents a two-dimensional electron gas. We have considered a linear motion of a particle both above the surface of nanotube and along its axis (Cherenkov radiation mechanism). Yakovenko V.M., Dormidontov A.V., Prokopenko Yu.V., Khankina S.I.
  2. The problem of the transition radiation of an electron moving along the normal to the interface between an isotropic dielectric and a layered superconductor has been theoretically examined. It has been assumed that the layers of the superconductor are perpendicular to the interface. At azimuth angles 0o < ϕ < 90o  the radiation field of excited bulk electromagnetic waves is shown to be a superposition of the ordinary and extraordinary electromagnetic waves. At angles ϕ ≈ 0o  and ϕ ≈ 90o  the radiation field becomes TM polarized. At ϕ = 0o  the position of the maximum of the spectral energy density varies with frequency over a wide range of the tilt angle  ϑ.  At ϕ = 90o  the position of the maximum of the spectral energy density is close to ϑ ≈ 90o  for all frequencies which have a physical meaning. It has been established that for the case under study the Vavilov-Cherenkov radiation generated by the electron entering the layered superconductor cannot be reversed. Besides, the so-called oblique surface electromagnetic waves can also be excited along with the bulk waves. Averkov Yu.O., Yakovenko V.M., Yampol’skii V.A..
  3. We have theoretically studied oblique surface waves (OSWs) which propagate along the interface between a dielectric and a layered superconductor. We assume that this interface is perpendicular to the superconducting layers, and OSWs at the interface can propagate at an arbitrary angle with respect to them. The electromagnetics field of the OSWs in a layered superconductor is a superposition of an ordinary wave (with its electric field parallel to the layers) and an extraordinary wave (with its magnetic field parallel to the layers). We have derived the dispersion equation for the OSWs and shown that the dispersion curves have end points where the extraordinary mode transforms from evanescent wave to bulk wave, propagating deep into the superconductor. In addition, we have analytically solved the problem of the resonance excitation of the OSWs by the attenuated-total-reflection method using an additional dielectric prism. Due to the strong current anisotropy in the boundary of the superconductor, the excitation of the OSWs is accompanied by an additional important phenomenon: The electromagnetic field component with the orthogonal polarization appears in the wave reflected from the bottom of the prism. We show that, for definite optimal combinations of the problem parameters (the wave frequency, the direction of the incident wave vector, the thickness of the gap between dielectric prism and superconductor, etc.), there is a complete suppression of the reflected wave with its polarization coinciding with the polarization of the incident wave. Contrary to the isotropic case, this phenomenon can be observed even in the dissipationless limit. In such a regime, the complete transformation of the incident wave into a reflected wave with orthogonal polarization can be observed. Averkov Yu.O., Yakovenko V.M., Yampol’skii V.A., Nori F.
  4. The electrodynamic analysis of cylindrical dielectric resonator (CDR) with forced "whispering gallery" oscillations was made when they are excited by an azimuthal-periodic current source. A relativistic electron beam propagating parallel to the cylindrical surface of resonator was used as a current source. The computer program for displaying the field distribution of forced modes in resonator when an electric current pass in the axial direction of resonator axis both in inside and outside was designed and debugged. It was continued to develop the self-consistent nonlinear excitation theory of the electromagnetic radiation of millimeter wavelength range in a radially-two-layer shielded CDR by a high-current azimuthal-periodic relativistic electron beam (REB). A cylindrical metal shield is required to create a vacuum environment in which the electron beam propagates.
Nonlinear numerical analysis was made. The main purpose of numerical study was to analyze the excitation possibility of the millimeter wavelength oscillations by a multi-stream electron beam in a dielectric resonator that has the transverse dimensions larger than the wavelength of the excited mode. The multi-stream of electron beam has supported the azimuthal periodicity that allowed to select the excited resonator eigenmode on the azimuthal index. The parameters of the resonator under test were as follows: the radius of first layer with the permittivity of 2.04 was equal to 4 cm, the radius of second vacuum layer was 7.5 cm, and resonator length was 0.83 cm. The beam parameters were as follows: the number of streams was equal to 36; beam current and energy were equal to 1.5 kA and 300 keV, respectively. The analysis of the field in the resonator has showed that the main generation mechanism is the monotron mechanism when the particles are grouped in such a phase that in average they are given the energy at moving through the resonator. The maximum energy of the electromagnetic radiation was detected when the eigenmode of resonator is excited with the frequency of 34.117 GHz. At the same time, the efficiency of monotron mechanism and the coupling factor with the beam had the largest quantities. The eigenmode field distribution of shielded radially-two-layer resonator is fully consistent with the field distribution of open cylindrical dielectric resonator with the radius of 4 cm that is proof of the weak influence of the cylindrical metal shield on the excitation mechanism of the eigenmode of dielectric resonator. We have previously justified and developed an electronic self-oscillatory system based on the CDR with the "whispering gallery" modes, in which the flight time of an electron between the end walls of resonator is less than the half-period (or commensurate with an odd number of half-period) of its eigenmode. The high-Q CDR with conducting end walls was excited by a REB. The electromagnetic energy was extracted from the resonator by exciting a slit radiator situated at the rear end wall in maximum of HE36 1 l mode field localization (l = 0, 1, 2). A microwave radiation from the studied system in the 7…9 mm wavelength range was detected. The realized numerical analysis of an excitation of millimeter wavelength oscillations in a CDR by a multi-stream REB is fully consistent with the results of experimental studies. Thus, a further development of the principles of constructing millimeter wavelength radiation sources based on a high-Q quasi-optical CDR, in which electromagnetic "whispering gallery" modes are excited by an azimuthal-periodic flow of electrons, was implemented. The possibility of mode selection and of increasing of the excited oscillations frequency was shown by use the modulation of the electron beam in azimuth and the operation at higher resonator eigenmodes. It should be noted the decrease of the resonator radius and/or the use of the "whispering gallery" modes of higher order with respect to the azimuthal index would allow to realize the proposed or modified auto-oscillation system with acceptable geometry parameters in the terahertz frequency range. Dormidontov A.V., Prokopenko Yu.V.
  1. The investigation of the nature of the spin-wave structures which can occur in acoustic resonator made of iron borate (FeBO3) in a field of the standing longitudinal sound wave has been continued. These studies are related to the piezomagnetics fundamental properties. It builds and substantiated. The model of the magnetic structures that are a result of the unpaired piezomagnetic connection has been built and validated. Tarakanov V.V.
  2. Experimental investigations of the forced whispering gallery modes in dielectric resonators of different forms were continued. Previous studies have shown that different conditions and methods of excitation of such oscillations have significant influence on the properties of dielectric resonators at the mode using of forced whispering gallery. Use of local radiation sources or coupling elements, located inside of the resonant fields, leads to the additional energy losses, and as a consequence, to decreasing of Q-factor of the resonator. Distributed coupling of external supplying elements with resonators can not achieve high efficiency of excitation of oscillations in the resonators. Therefore it was proposed a new type of coupling of double-layer (shielded) dielectric resonators (dielectric-metal) with the slot-line. The slot-line is formed by the thin slot gap between the flat base of the metal screen and metal mirror of the resonator. Dielectric resonator in this case presented a half-body rotation (cylinder, sphere). The local elements of the oscillation excitation are placed outside of the fields of shielded resonator.
The carried out investigation shown that this proposed method has high efficiency of the whispering gallery excitation in the shielded dielectric resonators and allows exciting the high-Q whispering gallery modes due to the absence of loss of the resonance field on a local coupling element. Kogut A.E., Nosatyuk C.O., Solodovnik V.A.
  1. Conduct experimental study of forced oscillations in multilayer open half-disk dielectric resonators. We investigated connected fluctuations in the group of the same Teflon half-disks with an air gap between them (the radius of the disk - 39 mm, thickness of disks - 0 mm), which carries on the different distance d from each other. Excitation of vibrations was carried out a rectangular gap connection section 0.2*7.2 mm installed in the metal mirror on which the half-disks. We measured the frequency response of the reflection coefficients of the two or three disks. The dynamics of transformation and the Q factor of the resonance curve, depending on the distance between the discs. Experimental results have shown that a system of open half-disk resonators driving unit in the form of a rectangular waveguide which is narrowed to a gap in the metal base, the electrodynamic system is compact with high efficiency excitation of forced oscillations. Krivenko E.
  2. In the study of the features of disk dielectric resonators in the form of cell dielectrometer to determine the dielectric properties of dielectric materials (particularly liquids), we drew attention to the possibility of using for this purpose a special design of disk dielectric resonator - plate disk dielectric resonator. Such resonator was proposed in 1984 by employees of the Moscow Energy Institute, but neither the quality factor of the resonators or the influence of liquids, which plunges a resonator still not been established. It was assumed that this design feature allows the resonator to improve communication with the environment surrounding the resonator cell and thereby increase its sensitivity to changes in the dielectric constant. In the pilot study we have found that the air gaps as axial discontinuities significantly increase radiation losses and lead to a reduction in the quality factor resonators almost two orders of magnitude.
The pilot found that varying the width of the air gap in the disk resonator consisting of two discs, one can observe an increase of merit with a gradual increase in width in the range from 0 to 0.4 mm in a few times. In this case, resonators made of polycor this feature appears clearer than in resonators made of quartz, as the absorption of the first material than the second material. To study the effect of fluid on the resonant frequency of the resonator plate was selected air gap between the two disks of polycor ~ 0.27 mm. With this gap plate resonator quality factor Q factor greater than conventional disk cavity more than twice (Q> 100). When immersed in the cavity of the plate-butanol and benzene, even whispering gallery resonances disappear. Only when introducing said fluids directly into the air gap failed to note lowering the resonant frequency of the cavity almost ~ 300 MHz. A further study on the effect of the resonance frequency is necessary to analyze the effect of the selected interval between the disks to increase the sensitivity of the plate resonator and improve the methodology and research equipment. Golubnichaya G.V, Kirichenko A.Y.
  1. The investigations of the resonators as waveguide-dielectric resonator (WDR) or waveguide-coaxial resonator (WCR) with the resonance short-circuit plunger (RSCP) have been carried out for the improvement electrical characteristics resonance structures of the waveguide dielectric type (eigen frequencies and Q-factors). Unlike of sample short-circuit plunger the conditions of the perfect electrodynamic contact between the plunger and waveguide walls are created in these resonators with the help of RSCP. This leads to the essential increase of the eigen Q-factor of the resonator during the frequency tuning of the oscillations. It has been shown in 2013 that in this way we can increase the eigen Q-factor of the oscillations both the waveguide-dielectric and the waveguide-coaxial resonator. An addition, it was shown that in 3-centimeter wavelength band because of the use of the RSCP the Q-factor of the fundamental magnetic oscillation H111 in the WDR was increased in several times. It is important that at the same time over the band of the frequency tuning the eigen Q-factor of the oscillation was invariable which is important in practical use. In scientific terms such studies allow us to study the conditions of the interaction of various types of resonance oscillations. On the basis of the given investigations the procedure for calculating of the resonators of the waveguide-dielectric type with the RSCP was developed, and the method for the calculation of the plunger and its design was proposed. As a result of the given investigations the characteristics of the WDR corresponding to the computed data have been obtained. Belous R.I., Martynyuk S.P., Motornenko A.P., Skuratovsky I.G., Khazov O.I..
  2. On the basis of the microwave impedance measurements, the temperature dependence of the complex conductivity of superconducting chalcogenide FeSexTe1-x was obtained and analyzed. The magnetic penetration depth exhibits a power-law behavior of, with an exponent n ≈ 2.4 at low temperatures, which corresponds to idea of s+/- symmetry of order parameter by analogy with pnictide BaFeCoAs where n=2.8. The first publication on microwave study of FeSexTe1-x film was prepared. The results are important to clear up the basic properties of novel unconventional superconductors.
The step dependence of microwave loss on temperature was found during studying nonlinear peculiarities of HTS-based coplanar transmission line (waveguide). The width of a step feature depends on power of pulsed microwave field. Nature of the peculiarity has not cleared up and demands the further research.The obtained results can have practical importance for HTS-based microwave technology and be important to study nonlinear properties of superconductors in microwave fields. A microwave characterization technique on the basis of a high-quality whispering-gallery mode (WGM) sapphire resonator with a microfluidic channel filled with the liquid under test was developed. The complex permittivity of aqueous solutions of proteins (cytochrome C, albumines) and glucose was measured depending on concentration with a high accuracy. The measurement technique is original. The results can be fundamental of a novel approach to dielectrometry of biological liquids on the whole and to dielectrometry of liquids of small volume specifically Barannik A.A., Gubin A.I., Lavrinovich A.A.,Protsenko I.A., Kharchenko M.S., Cherpak N.T.
  1. The theoretical study of the electrodynamic properties of the thin-film periodic structure, when the length of the electromagnetic wave propagating in the sample is much smaller than the period (so-called small-layered structure) was carried out. We analyze the structure which is formed by layers of the dielectric and semiconductor which has a frequency dispersion. It is assumed that it is placed in a constant external magnetic field. In addition, the properties of the plastic material can be controlled by physical and geometrical parameters of the structure. Small-layered periodic structure in a magnetic field is an optically biaxial crystal with effective components of the permittivity tensor, which depend on the physical parameters of layers and the thickness of the layers and the magnetic field. The dependences of the permeability tensor elements of the fine-layered structure on the frequency and magnetic field were studied. The analytical expressions for the characteristic frequencies and magnetic fields in which the tensor components are converted to zero or infinity were obtained. The dispersion properties of the semi-infinite and limited small-layered structure in a magnetic field, namely: the properties of the surface waves at different interfaces, polarizing and spectral properties were analyzed. The theory of the electrodynamic properties of a periodic dielectric structure with exciton layers was constructed. Bulgakov A.A., Fedorin I.V.
  2. The investigations of the transmission spectrum of the small-layered ferrite-semiconductor medium which is surrounded by a dielectric periodic structure were carried out. The properties of small-layered medium were previously analyzed. The regions in which this medium has the right-handed and left-handed properties were found. The influence of the external magnetic field and the component parameters of the investigated structure on its throughput property was analyzed. It is shown that by the changing of the external magnetic field can change the properties of the waves in the investigated The obtained results and the experimental data are in good agreement. As a result the investigated structure can be used, for example, in controlled microwave and optical devices. Vdovichenko O.V., Girich O.O., Bulgakov A.A., Tarapov S.I.
  3. Theoretical and experimental investigations (partially conducted at the National University of Ireland, Maynooth, Ireland, and Bilkent University, Turkey) directed at the development of the photonic crystals for the mmillimeter wavelength band that can switch with the light pulses and to which is added to the polarization sensitivity by superlattice structure of the semiconductor surfaces were carried out. In order to the increase of the interaction between the millimeter waves and the corresponding structures which are controlled by light the new types of the quasi-optical Fresnel lenses which have the two-sided stepped profile and the matched matched step profile on the different surfaces with the partial sizeof the steps in comparison with the Fresnel lenses of the traditional type have been proposed and experimentally investigated. The bilateral lenses with the partially size of the steps are not known analogues. Yurchenko V.B)
  4. The behavior of the two-level system in the presence of two periodic fields of different frequencies was studied in the rotating wave approximation. The interaction of the system with thermal bath was taken into account, which leads to damping and decoherence. The frequencies of the fields were considered to be close to the resonance frequency, the deviations being of order of damping constant. As the response of the two-level system to the periodic fields is non-linear, in the presence of the two fields the nonlinear effect of energy absorption by the one field and pumping it in the second field is possible. It is shown that this pumping is realized in the system, and the corresponding power is found in the limiting case when the amplitude of one of the fields is much greater than that of the other. In this case the equations defining the evolution of the field amplitudes were expanded into series and the analytical results for the power of energy absorption by the weaker field were obtained. The spectra of energy absorption were plotted and it is shown that for the specific ratio of parameters of the problem both positive and negative values of power are possible. In the case when the two frequency detunings have the same absolute values and different signs the spectra remind the well-known Mollow triplet. Maizelis Z.A.
  5. The spectral features of the structure fotonny crystal / ferrite / plasma-like media were experimentally investigated. The possibility of the occurrence of the surface electromagnetic states (SEMS) in the studied structure, which appear as the transmission pikes in the forbidden band of the photonic crystal, was shown. The influence of the parameters (ferrite layer thickness, the external magnetic field and temperature) on the frequency position of the transmission pike caused by the ESAP was experimentally studied. Kharchenko A.A.
  6. To study the seasonal and daily dependency of the refractive index of the troposphere, and the communication between him and the signal levels and satellite television center used data (temperature, humidity and pressure) regular meteorological stations different cities of Ukraine (about 100 cities). On the basis of these data, we calculated the value of the refractive index of the troposphere, a database of more than 500 thousand. Measurements characteristics studied and developed a statistical model of the refractive index, which takes into account his unsteadiness and non-Gaussian In addition, measurements were made of the refractive index using microwave radiorefraktometra at the location of measurement system A.Ya.Usikov IRE NASU. Krivenko E.V.
  7. The dependence of the pseudo-calculated level fluctuations and the availability of the height of the propagation path of GNSS signal bands of rain. The dependence of the performance of GNSS signals and changes their information options can be used to detect dangerous weather phenomena in the propagation path from the satellite to the user navigation that allows you to extend the functionality of GNSS receivers and increase their competitiveness. Krivenko E.V.

2014

  1. The surface electromagnetic states (SEMSs) on graphene, which has a linear carrier dispersion law and is placed in an antiferromagnetic photonic crystal, are theoretically studied in the terahertz frequency range. The unit cell of such a crystal consists of layers of a nonmagnetic insulator and a uniaxial antiferromagnet, the easy axis of which is parallel to the crystal layers. A dc magnetic field is parallel to the easy axis of the antiferromagnet. An expression that relates the SEMS frequencies to the structure parameters is obtained. The problem of SEMS excitation by an external TE-polarized electromagnetic wave is solved, and the dependences of the transmission coefficient on the dc magnetic field and the carrier concentration are constructed. These dependences are shown to differ substantially from the case of a conventional two-dimensional electron gas with a quadratic electron dispersion law. Thus, the positions of the transmission coefficient peaks related to resonance SEMS excitation can be used to determine the character of carrier dispersion law in a two-dimensional electron gas. Averkov Yu.O., Tarapov S.I., Yakovenko V.M., Yampol’skii V.A.
  2. We theoretically study the transition radiation of bulk and surface electromagnetic waves by an electron crossing an interface between a layered superconductor and an isotropic dielectric. We assume that the direction of the electron motion and the orientation of the superconducting layers are perpendicular to the interface. We derive the analytical expressions for the strongly anisotropic radiation fields and for the time-integrated energy fluxes of bulk and oblique surface electromagnetic waves (OSWs). We show that the OSWs with frequencies close to the Josephson plasma frequency ωJ provide the main contribution to the OSWs energy flux. Moreover, for frequencies close to the Josephson plasma frequency, the spectral density of the OSWs radiation diverges at some critical value of the azimuth angle ϕ. At the angles ϕ = 0 and ϕ = 90o, the radiation field has a transverse magnetic polarization. We have also studied the Cherenkov radiation by the electron escaping from the layered superconductor and show that this radiation is almost monochromatic. A remarkable feature of the Cherenkov radiation in a layered superconductor is that, contrary to the isotropic case, the Cherenkov radiation distinctly manifests itself in the angular dependence of the radiation energy flux. Averkov Yu.O., Yakovenko V.M., Yampol’skii V.A.
  3. The energy loss of an electron moving above a graphene layer in vacuum by excitation of surface electromagnetic waves of TM- and TE-types has been calculated. The obtained results have been used for calculation of instability increments of charged-particle fluxes moving above a graphene layer. Averkov Yu.O., Yakovenko V.M.
  4. We predict the coexistence of localized TE-and TM-polarized surface electromagnetic waves in a PC-graphene-PC structure. These waves can propagate in the same frequency range due to the zone structure of the photonic crystal, in contrast to the waves localized near the graphene layer placed between two identical dielectrics. In the latter case, the TM and TE surface waves can propagate in different frequency ranges. We also consider the excitation of localized TM and TE modes by the external wave that irradiates the PC-graphene-PC structure. We show that independent of the polarization of the exciting wave, the resonance peak of the transmissivity of the structure appears when changing the frequency or the incident angle. The analysis of the resonance peaks of the wave transmissivity can provide important information on the graphene conductivity in the centimeter, millimeter, and submillimeter wavelength frequency ranges. Averkov Yu.O., Yakovenko V.M., Yampol’skii V.A., Nori F.
  5. The energy losses by a charged particle moving along a spiral path above the surface of a dielectric cylinder due to excitation of the cylinder eigenmodes have been considered. The fields excited by the charged particles and their structures have been studied. When the particle moves along a spiral path in a constant magnetic field, it can be considered as an oscillator the field of which depends on an angular coordinate. The spectral component of the field (in comparison with a linear motion) is characterized by the azimuth wavenumber. The longitudinal and transversal wavenumbers depend on the sign of the azimuth wavenumber (this is the feature of the particle field). Thus, all of the infinite set of the spectral field components divides into two groups depending on the azimuth wavenumbers. For one of them the transversal wavenumbers are real values. These spectral components are waves propagating from the particle. They cause the energy losses of the particle in vacuum (magneto-bremsstrahlung). We have shown that the presence of metallic cylinder results in decrease of the energy losses due to the interference in the point of the particle of the radiated and reflected waves. The second group of the spectral field components with real wavenumbers causes the energy losses of the particle by the excitation of the eigenmodes in dielectric cylinder. The waves in the middle of the waveguide are characterized by the real wavenumbers. The universal expressions for energy losses of the moving particle have been obtained. The various cases such as energy losses by the charged circle under its translatory motion, energy losses by the charged particle along a spiral path above metal or dielectric cylinder have been analyzed. The conditions for occurring of the magneto-bremsstrahlung have been formulated. Khankina S.I., Yakovenko V.M.
  6. In order to understand the mechanism of excitation waves in a dielectric or semiconducting cylinder on the side of which there is a layer of two-dimensional electron gas (2D-gas), the energy losses of a charged particle moving along a spiral path around the cylinder in an external magnetic field were determined. The availability of 2D-gas creates the conditions for the existence of electrostatic waves in the system. Such layer can be created by using a conductive thin film on the surface of a dielectric or semiconductor. It also can be created, for example, by a periodically uneven surface along an element of semiconductor cylinder. At the same time, the region of field localization exceeds the height of the surface roughness.
It is shown that in this system it is possible to excite the eigenwaves of electrostatic origin. It was noted and justified that in dielectric cylinder these waves appear only in the presence of 2D-gas. The excitation is implemented in conditions of gyrosynchrotron resonance, when the frequencies and the longitudinal wave numbers of charged particles waves and eigenwaves of system are same. In this case, the frequency of the excited wave  (where  is the longitudinal wave number of the excited mode with azimuthal index;  is the translational motion velocity of the particles along the symmetry geometrical axis of cylinder;  is the cyclotron frequency of the particle in a magnetic field) satisfies the dispersion equation of the structure under study. In result, there are the energy losses of a charged particle. The features of the Doppler effect have been found. It is shown the selection of excited modes can be carried out by the selection external magnetic field. The formula for the energy losses of a particle in a unit of time has been obtained and analyzed. The dependencies of losses were studied at various parameters namely the azimuthal index of the excited modes and the external magnetic field. This formula is universal. From it is possible to obtain the energy losses during the rotational movement of the particle as well as during the forward movement of the charged particles or ring that encircles a cylinder. It can be used to describe the energy losses on the excitation of eigenwaves (natural oscillations) in various cylindrical structures with 2D-gas and semiconductor cylinder. For this purpose, we have made numerous studies of the dispersion equations and constructed the frequency dependencies of eigenmodes for various parameters of corresponding systems under study. It was noted the spectrum of the structures eigenfrequencies corresponds to a finite set of harmonics with the azimuthal indices of , where  is the radius of cylinder, and  is the radial thickness of 2D-gas. It is shown the present plasma layer on the side surface of  semiconductor cylinder increases the eigenfrequencies of the structure and the intermode frequency interval in its spectrum compared to the semiconductor cylinder. The eigenfrequencies of structures under study decreases with increasing a dielectric constant  of cylinder. It was found the eigenfrequencies of semiconductor and dielectric cylinder with 2D-gas that have the radius less than 10-5 cm and the identical dielectric constants  are in the near infrared range. The frequency difference of the identical eigenmodes of these structures does not change substantially when the longitudinal wave numbers are synchronously changed. Yakovenko V.M., Dormidontov A.V. Prokopenko Yu.V., Khankina S.I.
  1. Work on the text of the book "The problem of the piezomagnetism in weak ferromagnets"was continued. The weakly ferromagnetic mL addition to the Landau energy on its connection with heterogeneous and variable in sign the piezomagnetic powerful strains of the type ezz was studied Tarakanov V.V.
  2. The excitation of the shielded dielectric resonators of different forms by the slot-line for the studying of their electromagnetic properties was used. Based on the proposed use of the slot-line the measuring cell of millimeter wave dielectrometer for investigation of electrical properties of liquids was proposed. The results of carried out investigations have shown that in contrast to the existing methods of modes excitation in shielded dielectric resonators the using of slot-line allows maximum rarefying the spectrum of forced oscillations with priority excitation of whispering gallery modes. The application of slot-line in dielectrometry for determining the dielectric constant of liquids with similar physical properties has improved sensitivity and resolution of the measurements. Kogut A.E., Nosatyuk S.O., Dolya R.S.
  3. Conduct experimental study of forced oscillations in multilayer open half-disk dielectric resonator with discontinuities in the form of a metal rod, which is located on the curved plane of the resonator. We measured the frequency response of the reflection coefficients of the two or three disks, depending on the angle of the metal rod. The dynamics of transformation and the quality factor of the resonance curve, depending on the distance between the disks and the position of the rod. The registration transmission coefficients and the scattering of light by different water samples at several wavelengths in the optical range experimentally conducted. Turbidity is usually accompanied by a change in its color (blue to yellow), then the sensors used several wavelengths (650nm - red, 550nm - green 450nm - blue and infrared - 850nm and 940nm). Measurement of attenuation at different wavelengths carried monophonic receiver, sequentially in time. To improve noise immunity against external light sources used by low-frequency modulation of the radiation source and the narrowband synchronous receiving radiation transmitted through the sample. Using the multi-wavelength mode allows you to increase the accuracy of measurements and to differentiate the size of the dust. Krivenko V.
  4. The difference of the electrical characteristics of the water sources of the Kharkiv region used in the circuits of dielectrometry of millimeter wave range of the measuring cell in the form of a capillary-waveguide resonators and vibrating string was set. In contrast to the statement about lowering the quality factor quasi-optical resonators when they are created or introduced heterogeneity, identified an opportunity to improve the quality factor of the disk dielectric resonators when creating axial cracks of a certain size, separating the resonator on 2 discs. It was established experimentally new features of betweentype of vibrations of the disk dielectric resonators in a "purely internal" excitation of spurious modes by additional disturbing elements. In submitted to the publishing house "Naukova Dumka" monograph the results on the microwave dielectrometry biotechnologycal liquids made in recent years in the Department together with the staff of the Kharkov national University. V. N. Karazin is summarized Kirichenko A. Ya., Golubnichaya G. V.
  5. The investigations of the electrical characteristics of the resonanse structures based on evanescent waveguides were continued. As a result the new peculiarities of the waveguide-dielectric resonator (WDR) with a resonance short-circuit plunger (RSCP) were founded. We proposed RSCP for the increase of the eigen Q-factor of the fundamental asymmetric magnetic oscillations in the WDR. As it turned out, the detected peculiaritis are caused by the interaction of two types of electromagnetic oscillations: the fundamental oscillation in the WDR and oscillation which is excited with the short-circuit plunger under certain conditions. The conditions of the interaction of two oscillations were investigated, as well as the conditions under which such interaction becomes impossible. On the basis of the given investigations new more stringent conditions related to the calculation of RSCP to create WDR with high Q-factor over the band of the frequency tuning for the resonance H111 oscillation were formulated. The validity of the proposed calculations was confirmed with the experimental investigations. The preliminary investigations of the possibilities of the creation of the WDR with RSCP in the millimeter wavelength band which showed the availability of this direction and the reasonability to continue investigations in the future have been carried out. Belous R.I., Motornenko A.P., Skuratovsky I.G., Khazov O.I., Shahova A.C.
  6. By continuing study of the nonlinear properties of a coplanar transmission line (CPL) on the basis of HTSC YBaCuO thin film, the authors found quenching transition to a strongly dissipative state of CPL by passing DC through it. An important feature of the observed effect is its non-destructive character. In this case the superconducting properties are restored when the power of the microwave signal or DC value decrease. The authors assume that the nature of the effect may be due to self-heating HTS thin film structure caused by magnetic flux flow with an overall effect of microwave and DC currents. The effect may have scientific significance in the field of nonlinear radio physics and applied importance for microwave technology Gubin A.I., Lavrinovich A.A., Cherpak N.T.
  7. By developing microwave dielectrometry based on high-Q WGM resonators for study of lossy bioliquids with small volumes, the authors have developed an approach to solving the inverse electrodynamic problem under conditions when the Q-factor and frequency of the resonator depends on both the real and the imaginary part of permeability of liquid under test. The method can be of practical significance for the study and testing bioliquids of small volumes. Barannik A.A., Gubin A.I., Protsenko I.A.
  8. Investigations of the electromagnetic waves propagation in a photonic crystal with the small-layered ferrite-semiconductor inclusion were carried out. The system is placed in an external magnetic field directed along the surfaces of the layers. The results of the analytical and numerical studies show that for the proposed structure the effective controlling with the spectral and polarization properties of the electromagnetic wave which is reflected and which passes (phase difference, the angle of rotation of the polarization and ellipticity) it is possible using of the different parameters of the system, namely, the magnetic field, the layers thickness and physical parameters of the materials that form the photonic crystal and the metamaterial. Due to these properties the proposed structure can be used in the development of such devices as a polarizers, an adder-splitters and others. Vdovichenko O.V Fedorin I.V, Bulgakov A.
  9. The theoretical and experimental investigations directed at the developing of the new methods for the measuring the the dielectric parameters of the thin films using a quasi-optical disk resonators, which have the additional resonant substructures have been made. Due to the new effects the increase of the sensitivity of these methods are expected. Yurchenko V.B.
  10. The evolution of microresonator in the presence of external periodic force and telegraph frequency noise in the regime close to resonance was It is shown that the detection of frequency noise on the background of the amplitude noise is possible by studying the higher moments not of the coordinate or the velocity but rather its complex coordinate. These quantities are not affected by the additive noise so even in the situation when they prevail and determine the spectrum of coordinate, the higher moments of the complex coordinate are nonzero only due to the presence of frequency noise. The time dependence of these moments one can not only detect the frequency noise but also find its characteristics. It was analyzed on the example of the telegraph noise, how its parameters, the characteristic frequency and amplitude of jumps affect the higher moments spectra. The obtained theoretical curves well correlate with the experimental data obtained for the torsion microoscillator in the presence of the telegraph frequency noise. Maizelis Z.A.
  11. The temperature dependence of the complex electron conductivity was obtained and the value of two energy gaps were found for chalcogenide superconductor FeSeTe. The study was conducted for a thin (100 nm) epitaxial film. The results are qualitatively consistent with the results in the study of a single crystal FeSeTe by other authors, but there are significant differences that need to continue with the aim of consensus conclusions Barannik A.A., Cherpak N.T.
  12. We consider the seasonal changes in the characteristics of the troposphere and the ionosphere for different regions of Ukraine. It was found that the refractive index is characterized by a strong diurnal and seasonal dependency caused by changes in temperature, pressure and humidity. It is shown that in the winter for all cities, regardless of their location troposphere refractive index has a value of about 310 units of N, while its summer maximum values depend on the location of the city. The models that are used to analyze spatial and temporal variations in the characteristics of the ionosphere were considered. A database of GNSS measurements for different seasons, allowing experimental research to develop and analyze the efficiency of the algorithms reduce measurement errors coordinate and develop methods of diagnostics atmospheric phenomena using GNSS. Krivenko E.V.


2015

  1. Electron energy loss by the excitation of surface magnetoplasma oscillations by an electron moving along a static magnetic field in vacuum over a two-dimensional plasma layer on the surface of three-dimensional plasma half-space has been studied theoretically. Electron energy loss by the excitation of surface magnetoplasmons has been calculated in the electrostatic approximation. It has been shown that the type of the dispersion law of electrons in such a plasma (quadratic for a two-dimensional Drude gas or linear for graphene) can be determined from the qualitative character of the dependence of the maximum of the spectral density of this loss on the electron density in the two-dimensional plasma. Yu.O.Averkov, Yu.V.Prokopenko, V.M.Yakovenko.
  2. Fast charge energy losses for the excitation of natural oscillations in media with a 2D plasma sheath are studied. A semiconducting (dielectric) cylinder-2D plasma sheath-vacuum system is considered. Dispersion relations describing natural oscillations in such a system are derived. Energy losses of a point charge rectilinearly and uniformly moving over and inside the cylinder are found. The loss of energy by a moving charged ring embracing the system (specifically, a nanotube) is considered. Dormidontov A.V., Prokopenko Yu. V., Khankina S. I., Yakovenko V. M.
  3. In electrostatic approximation the dispersion equation describing the eigenmodes of semiconductor cylinder with the layer of two-dimensional electron gas on the side surface (3D+2D-plasma) has been obtained. The energy loss of charged particle were found when it moving into external magnetic field that has the intensity vector parallel to the symmetry longitudinal axis of the 3D+2D-plasma of cylindrical configuration. It was noted the obtained relation has the universal character. From it the energy loss in both of a rotary motion of particle around the cylinder and its translational motion parallel to the cylinder generatrix may be obtained. The effect of non-reciprocity of the eigenmodes excitation of 3D+2D plasma cylinder was discovered. These modes have identical structures of the field distribution, but differ in the propagation direction along the azimuthal coordinate. Dormidontov A.V., Prokopenko Yu. V., Khankina S. I., Yakovenko V. M.
  4. The new method for efficient excitation of the whispering gallery modes (WGMs) in shielded quasioptical dielectric resonators (QDRs) by a planar waveguide formed by the plane of the metal mirror of the resonator and the flat base of its metal shield is proposed. It has been experimentally established that the proposed method for exciting WGMs by the planar waveguide in the shielded QDRs is a low-perturbation method in comparison with known excitation methods for WGMs in closed resonators. A.Y. Kogut, S.O.Nosatuk, R.S.Dolya, He Jaochan.
  5. A scheme for stabilizing the frequency of solid-state sources in the millimeter range based on the hemispherical shielded QDR by using a planar waveguide is proposed. It is established that such a scheme, due to a small perturbation of the resonant fields of the WGMs, makes it possible to significantly improve the possibilities for frequency stabilization in comparison with the known schemes that assume the location of the solid-state source directly in the field of operating oscillations in the resonator. A.Y. Kogut, S.O.Nosatuk, R.S.Dolya, He Jaochan.
  6. Continuing the investigation of an avalanche-like transition into the strongly dissipative state of the coplanar transmission line (CPL) based on a thin YBaCuO high-Tc superconductor film, the authors experimentally showed a nontrivial dependence of the effect on the thickness of the HTSC film. This may be a confirmation of the correctness of the previously stated hypothesis about the thermal mechanism of the detected effect under the combined effect of microwave and direct currents. A.A Lavrinovich, N.T Cherpak.
  7.  The first results showing the possibility of developing sub-THz dielectrometry of small-volume liquids based on quartz quasi-optical resonators are experimentally obtained. The results can stimulate the development of dielectrometry of small-volume biological fluids in the sub-THz waveband based on the KDR. A.I. Gubin, A. A. Barannik, I.A. Protsenko.
  8. Experimental studies have been carried out to reconstruct an image obtained through a turbid medium. Based on the obtained integral distribution functions (test and distorted by the medium), a correcting function was constructed, on the basis of which the restoration was carried out. The proposed approach can be useful in solving the actual problem associated with increasing the informativeness of methods for optical diagnostics of remote monitoring systems for biological tissues in medicine and for the environment in radiophysics and geophysics. E.V.Krivenko.
  9. The influence of the telegraph noise on the high-order moments and the correlation function of the electromechanical microresonator are studied. It is shown, that not only it is possible to detect the presence of the frequency noise, but also to find its characteristics from the measured dependence of the system response on the frequency of the external pumping. Z.A.Mayzelis.
  10. The characteristics of the manufactured waveguide-dielectric resonator (WDR) on the basis of the evanescent waveguide with a resonant short-circuit (SC) plunger in the millimeter wavelength range are studied. Conditions for the interaction of two types of electromagnetic oscillations (the fundamental oscillation in the WDR and the oscillation excited by the plunger under certain conditions) have been found. R. I. Belous, I. G. Skuratovskiy, O. I. Khazov, A. S. Shakhova, M.V. Vovnyuk.

 


2016

  1. In this paper, we have performed a theoretical analysis of dispersion properties of the surface helicons in the structure with the graphene monolayer lying on the surface of the 3D plasma. It has been found that the presence of the graphene monolayer gives rise to the portions of dispersion curves with anomalous dispersion of the surface helicons. These portions do not occur in the case where the 2D plasma layer is a Drude plasma. Besides, it has been demonstrated that the collisionless damping of the surface helicons occurs when the wave frequency becomes larger than a certain critical value. The damping is caused by the transitions of the electrons in the graphene monolayer from the valence band to the conduction band. Yu.O.Averkov, V.M.Yakovenko. 
  2. The detailed theoretical description of the instability effect of non-relativistic infinitely thin hollow electron beam which moves in vacuum above a dielectric (plasma) cylinder has been done. The calculations have been performed in electrostatic approximation due to the non-relativistic velocity of the beam. The cases where the dielectric permittivity is constant and depends on the frequency have been considered. The dispersion curves of exited modes have been built. The dependencies of the increments (decrements) of the modes on the value of the bunch radius and on the azimuth mode index have been studied. It has been shown that for both the dielectric and plasma media the largest values of the increments (decrements) of the excited modes occur for zero value of the azimuth mode index. The maximum values of the increments (decrements) decrease with increasing the azimuth mode index. It has been established that the frequency dependence of the dielectric permittivity leads to the absolute instability. This instability exists in the corresponding finite interval of the longitudinal wave number. Yu.O.Averkov, Yu.V.Prokopenko, V.M.Yakovenko.
  3. Nowadays a good deal of attention is focused on problems of generation of electromagnetic oscillations on the basis of the interaction of charged particles with the structures containing dielectric and plasma-like media. This is due to the sufficiently high conversion efficiency of kinetic energy of the electron beam to electromagnetic radiation. The currently available theoretical results give only the qualitatively descriptions of experiments. Therefore, it is important to give a detailed description of such effects as close to the real conditions of the experiment. In this connection the detailed theoretical study of the instability of the non-relativistic infinitely thin tubular beam of electrons moving in a vacuum above a dielectric cylinder has been performed. It has been shown that either Cherenkov effect or anomalous Doppler effect occurs in relation to the distance (the impact parameter) between the beam and the dielectric. Yu.O.Averkov, Yu.V.Prokopenko, V.M.Yakovenko.
  4. By using a planar waveguide, it has been experimentally proved the possibility of exciting "superhigh -Q" WGMs in two-layered hemispherical shielded QDR. It is established that for certain sizes of the metal shield of such resonator and a half-ball dielectric structure, a unloaded Q-factor is achieved that exceeds the threshold value due to dielectric losses. It is shown that the reason for this is the partial displacement of the resonant field of the WGMs from the dielectric to the air gap. A.Y. Kogut, S.O.Nosatuk, R.S.Dolya.
  5. The design of a measuring cell of a dielectrometer based on a hollow hemispherical shielded QDR for the investigation of liquids with similar electrical properties is proposed. It is established that, due to the use of a planar waveguide to excite the operating WGMs in a shielded resonator, it is possible to minimize external factors of perturbation of the resonant fields, and, thereby, to achieve high measurement sensitivity. A.Y. Kogut, S.O.Nosatuk, R.S.Dolya.
  6. Continuing the investigation of an avalanche-like transition into the strongly dissipative state of a high-Tc superconducting coplanar waveguide (CPW), the authors experimentally confirmed the dependence of the effect on the thermal mechanism by placing an absorbing material located on the opposite side of the HTSC structure, under the combined action of microwave and direct currents. The results can have scientific significance in the field of nonlinear radiophysics and applied importance for microwave technology. A.A. Lavrinovich, A.I. Gubin, N.T. Cherpak.
  7. A new type of bandpass filter based on high-temperature superconductors in the millimeter wave band has been proposed and experimentally investigated. A. A. Barannik, N.T. Cherpak jointly with the employees of department 21 (V.N. Skresanov's group in Department 21).
  8. The existence of a connection between the value of the imaginary part of the dielectric constant of the absorbing medium partially filling the resonator with the steepness of the electronic frequency tuning of the oscillator stabilized by the resonator is proved theoretically and experimentally. This allows us to use a fundamentally new approach for measuring the imaginary part of the dielectric constant of the medium partially filling the resonator.
  9. Experimental studies of the previously proposed approach to the restoration of a distorted image by a turbid medium are carried out, which is based on the use of a priori information on the type of distributions in the presence and absence of distortions. E.V.Krivenko.
  10. As opposed to the balanced noise, the average for which is zero, the parameters of non-balanced noise are harder to detect from the high-order moments of the response function of the system. It is shown that study of both binary and third order correlation function allows to solve this problem. Z.A.Mayzelis.
  11. A comparative analysis of two methods of the measurement of the low relative permittivity (1,02 ÷ 1,1) of materials using a cylindrical waveguide-dielectric resonator on the evanescent waveguide was carried out. In one method, the test material is used as a dielectric element of the resonator. In another method proposed in this paper, the dielectric element has been made from ftoroplast, and the test material filled the evanescent sections of the waveguide. Results of measurements of the permittivity by both methods in the range 10 ÷ 12 GHz and the estimation errors were presented. R. I. Belous, I. G. Skuratovskiy, O. I. Khazov, A. S. Shakhova, M.V. Vovnyuk.

 


2017

  1. The interaction between a tubular beam of charged particles and a dispersive metamaterial of cylindrical configuration has been investigated theoretically. This metamaterial may have negative permittivity and negative permeability simultaneously over a certain frequency range where it behaves like a left-handed metamaterial (LHM). The dispersion equation for the eigenmodes spectra of a metamaterial and the coupled modes spectra of the system have been derived and numerically analyzed. It has been found that the absolute beam instability of bulk-surface waves occurs because of peculiarities of the eigenmodes spectra of LHM. Specifically, the resonant frequency behavior of the permeability causes the emergence of the sections of dispersion curves with anomalous dispersion. It has been demonstrated that the symmetric bulk-surface mode with two field variations along the cylinder radius possesses the maximum value of instability increment. The obtained results allow us to propose the LHM as the delaying medium in oscillators of electromagnetic radiation without a need to provide an additional feedback in the system just as in a backward-wave tube (Yu.O.Averkov, Yu.V.Prokopenko, V.M.Yakovenko).
  2. The interaction between a tubular beam of charged particles and a nonmagnetic anisotropic dispersive medium of cylindrical configuration has been theoretically investigated. The dispersion equations for the eigenmodes spectra of a medium and the coupled electromagnetic modes spectra excited by the electron beam have been derived. It has been found the absolute instability of bulk-surface waves that occurs because of peculiarities of the anisotropic cylinder properties. The resonant behavior of the permittivity frequency dependence causes the emergence of the sections of dispersion curves of the E-type bulk-surface eigenmodes with negative group velocity. It has been shown there are the E-type surface eigenmodes and pseudo-surface eigenmodes of E- and H-types in the cylinder. It has been demonstrated that the E-type bulk-surface hybrid whispering gallery modes with three field variations along the radial coordinate possess the maximum values of instability increments. The obtained results allow us to propose the anisotropic dispersive media as the delaying structures in oscillators of electromagnetic radiation without a need to provide an additional feedback just as in a backward-wave tube (Yu.O.Averkov, Yu.V.Prokopenko, V.M.Yakovenko).
  3. The investigations of a new class of small-sized dielectric resonators (DRs) - planar disk DRs, whose height is less than the threshold values allowing the excitation of WGMs in them have started. Such resonator is thin (in comparison with the wavelength) dielectric disc located between two conducting surfaces. It has been established experimentally and by computer simulation that WGMs are excited in such resonators with high efficiency. A.Y. Kogut, I.Y.Kuz’michev, S.O.Nosatuk, R.S.Dolya, Y.A.Shul’ga, He Jaochan.
  4. The design of a small-sized solid-state oscillator for Ka waveband based on the planar DR is proposed. It is established that such oscillator has a high short-term stability of the frequency - 5x10-6 and it’s characterized by high power - up to 100 mW. A.Y. Kogut, I.Y.Kuz’michev, S.O.Nosatuk, R.S.Dolya, Y.A.Shul’ga, He Jaochan.
  5. A new type of quasi-optical dielectric resonator (QDR) was first created and experimentally investigated, namely, a microstrip QDR based on a film of a high-temperature superconductor. A. A. Barannik, N.T.Cherpak (jointly with Nat. Lab. at IOP CAS).
  6. By numerical experiment, radiation losses of KDI as sensors for measuring microwave properties of dielectric liquids and unusual superconductors have been determined. The value of the complex permeability of a number of biological fluids characterized by large losses and small volume is obtained. For the first time measurements were made in mm and subTHz bands using a quasi-optical dielectric resonator with a microflute channel. A.I. Gubin, I.A. Protsenko (jointly with Prof. S.Vitusevich’s group at Institute of Bioelectronics, Juelich, Germany).
  7. Quantitative characterization of the influence of the magnetic field on the microwave nonlinear properties of the high-voltage transmission of coplanar transmission line in conditions of strong signal is obtained. A.A Lavrinovich.
  8. The possibility of the modeling of artificial intelligence with a register of quantum two-level systems with account of their decoherence. As opposed to the standard approach to quantum calculations, in which evolution is considered to be Hamiltonian, this approach allows the more precise modeling of quantum neuron network operation. Above that, the account of the decoherence not only enhances the realism of the calculations, but also leads to the acceleration of the algorithm. Z.A.Mayzelis.
  9. The problem of increasing the Q-factor of the waveguide-coaxial resonator (WCR) on the basis of an evanescent waveguide was solved. The new design of the WCR with a resonant short-circuit plunger was proposed. Using one of the types of constrictor plungers, we were able to reduce losses in the contact zone between the piston and the walls of the waveguide and to increase the Q-factor of the WDR. R. I. Belous, I. G. Skuratovskiy, O. I. Khazov, A. S. Shakhova.

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