1. Analysis of impulse fields reflected from layered medium with losses using artificial neural network Shyrokorad D. V., Dumin O.M., Dumina O.O., Katrich V.O. time domain, artificial neural network, impulse fields, layered medium Vestnik KhNU ¹883 Pages. 3540
The problem of determination of thickness a layer of layered medium by impulse irradiation is solved. The impulse fields reflected from the layered medium with electrical characteristics close to the characteristics of human skin are analyzed by artificia
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2. Experimental study of diffraction of electromagnetic waves on the lattice of elements of the complex profile Ivanchenko D.D., Maleev M. N. the difraction electromagnetic waves, chiral grates, frequencypoiarization property Vestnik KhNU ¹883 Pages. 5458
In given paper the diffraction of electromagnetic waves on volume grid is investigated experimentally. The grid consists of rectangular elements. Two planes of twodimensional periodic rectangular metallic string elements located on both dielectric surfac
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3. About convergence of the mode expansions onto spherical harmonic in time domain Kochetov B.A., Butrym A.Yu. mode basis method, transient field, spherical modes, ring current Vestnik KhNU ¹883 Pages. 4144
The convergence of spherical mode expansions in the time domain to the exact solution is shown on an example of a test problem that has a closedform solution. Radiation of a ring with transient current in free space is considered. It was shown that there
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4. Construction of mode basis for open dielectric structures by integral equation method Legenkiy M.N., Butrym A.Yu. mode basis method, open waveguide, eigenmode Vestnik KhNU ¹883 Pages. 5053
A new method based on integral equation formulation is proposed for construction of mode basis in open dielectric waveguides. Decomposition of the spectrum in such structures into discrete (surface wave) and continuous (volume wave) part is analyzed. Disp
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5. FREQUENCY MULTIPLICATION AT IMPUCT IONIZATION IN TRASFER ELECTRON DIODES ON BASIS AlN, InN E. D. Prokhorov, O.V. Botsula, I. A. Grishchenko AlN, GaN, InN diodes, frequency transformation factor , drift velocity, harmonics. Vestnik KhNU ¹883 Pages. 3034
Multiplication of frequency at impact ionization in intervalley transfer electron diodes on basis InN, AlN is considered. The current – voltage characteristics of intervalley transfer electron diodes have negative conductivity region and strong increasing
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6. Investigation of different temperature modes of auxilliary cathode work in magnetrons with cold secondaryemission cathode Avtomonov N.I., Vavriv D.M., Sosnytsky S.V. Magnetron, cathode, thermionic cathode, thermo emission, temperature Vestnik KhNU ¹883 Pages. 7382
A theoretical investigation of the emission current temperature dependence of the auxiliary cathode in magnetrons with cold secondaryemission cathodes is performed. Different methods of providing a spatialcharge limited emission from the auxiliary catho
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7. Quantum efficiency spectral chracteristics of resonant cavity photodector taking into account thermal gradient S.V. Gryshchenko, Resonant cavity photodetector, refractive index, temperature shift Vestnik KhNU ¹883 Pages. 811
In paper a theoretical analysis of quantum efficiency of resonance InGaAs/GaAs Pin photodetector (RCE PD) is presented. A mathematical model plugs in itself the transfer matrix method, heat conductivity calculation and dependence of index of refraction
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8. Determination of optimal parameters of a magnetocardiographic hexagonal measuring grid A.Yu. Kostiev, A.Yu. Butrym, S.N. Shulga magnetocardiography, gradiometer, current dipole, sensitivity, Hessian Vestnik KhNU ¹883 Pages. 2529
The article considers hexagonal grid of gradiometer sensors of magnetic field. The aim of the study is to determine the optimal parameters of the grid and the gradiometers in order to obtain maximum sensitivity of the measuring system in terms of location
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9. Longitudinal slot in a rectangular waveguide with dielectric layer parallel to wide walls A.A.Liakhovskyi slot, microwaves, waveguide, dielectric, admittance, scattering parameters. Vestnik KhNU ¹883 Pages. 5966
The longitudinal slot is cut in wide wall of rectangular waveguide with threelayer dielectric filling which parallel to wide wall is considered. The excitation problem is solved with modified eigen waves method. As eigen waves of the LM and LE modes ar
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10. ABOUT SPURIOUS RESONANCES IN PROBLEMS OF DIFRACTION WAVES ON WAVEGUIDE DISCONTINUITY Mizernik V.N., Shmat'ko A.A. spurious resonances, a branching of the waveguides, mathching uniformity, connection area, system of the linear algebraicequations Vestnik KhNU ¹883 Pages. 6772
In work it is shown, that the problem of existence of spurious resonances in problems of diffraction waveguide waves on various discontinue in waveguides is connected with incorrect representation of matrix elements of system of the linear algebraic equat
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11. Ballistic electronic transport in continuousband superlattice under applied electrostatic field S.I.Petrov, Klymenko M. V., Shulika O. V. ballistic transport, superlattice, effective potential Vestnik KhNU ¹883 Pages. 1219
We address in this work ballistic transport of electrons in semiconductor continuousband superlattice under applied electrostatic field. Combined influence of the effective mass periodically varied in space and external electrostatic field on the electro
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12. Dielectric permittivity profile reconstruction by frequency probing problem for a planelayered media with regard to dispersion Batrakov D.O., Simachov O.A. plane layered media, dispersion, inverse problem, dielectric permittivity Vestnik KhNU ¹883 Pages. 4549
In the present paper the problem of dielectric permittivity profile reconstruction with regard to dispersion is discussed. The nature of dispersion function is assumed to be known and unknown functions are real and imaginary parts of dielectric permittivi
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13. Microstrip structures with photonic band gap Fesenko V.I., Sukhoivanov I.A., Shul'ga S.N. photonics band gap, microstrip, filter Vestnik KhNU ¹883 Pages. 2024
In this paper, it is presented a twosided onedimensional photonic bandgap microstrip structure. The structure is obtained by etching a one periodic pattern of circles in the ground plane of a microstrip line and variation of the characteristic impedance
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14. The accumulation of gas in galactic objects Sorokin A.A., Sorokin A.F., Zaharova M., Sokolova O.V., Gorobets N.N. astrophysics, galactic objects, the accumulation of gas Vestnik KhNU ¹883 Pages. 37
The mechanism of the accumulation of gas in the galactic objects submerged in the largescale magnetic field is examined. As a consequence of the diamagnetism of the plasma subsystem of object, the stopper geometry of magnetic field with the radial electr
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15. Compromising emanations: overview and system analysis N.N. Gorobets, À.V. Trivaylo compromising emanations, nearfieldzone, electromagnetic, radiation, time domain Vestnik KhNU ¹883 Pages. 8388
The problem of compromising radiation of spurious signals in the near, intermediate and far zones of observation in time domain are considered. The Compromising emanation system analysis for finding spurious radiation is proposed. The goal of the given approach is to speed the development of technical protection of information. In approximation of the given current distribution it has been suggested a solution considering the influence of the nearfield effects upon directional characteristics of spurious signals radiation. The application of the new method allows us to investigate compromising of technical means in time and frequency domain.
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16. magnetron, cathode, thermionic cathode, thermo emission, temperature. Vestnik KhNU ¹883 Pages. 7382
A theoretical investigation of the emission current temperature dependence of the auxiliary cathode in magnetrons with cold secondaryemission cathodes is performed. Different methods of providing a spatialcharge limited emission from the auxiliary cathode are studied in order to eliminate the temperature dependence of auxiliary cathode thermionic current. A new design of the auxiliary cathode is proposed, which is supposed to provide a greater stability with respect to the cathode temperature variations as compared to the currently manufactured magnetrons.
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17. astrophysics, galactic objects, the accumulation of gas Vestnik KhNU ¹883 Pages. 37
The mechanism of the accumulation of gas in the galactic objects submerged in the largescale magnetic field is examined. As a consequence of the diamagnetism of the plasma subsystem of object, the stopper geometry of magnetic field with the radial electric field is formed. In this configuration, effective retention and the accumulation of the plasma, which revolves in the latticetype fields, occurs. Atoms are tightly connected on the effects of recharge with the ions, which provides their accumulation. The calculated distributions of molecular and atomic hydrogen in our Galaxy, whose the stopper geometry of its magnetic field is wellknown, are given. It is shown that this mechanism describes well the basic special features of gas subsystems
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18. Vestnik KhNU ¹883 Pages. 811
In paper a theoretical analysis of quantum efficiency of resonance InGaAs/GaAs Pin photodetector (RCE PD) is presented. A mathematical model plugs in itself the transfer matrix method, heat conductivity calculation and dependence of index of refraction from a temperature. Distributing of temperature in the structure of RCE PD and quantum efficiency taking into account the gradient of temperature was calculated.
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19. ballistic transport, superlattice, effective potential Vestnik KhNU ¹883 Pages. 1219
We address in this work ballistic transport of electrons in semiconductor continuousband superlattice under applied electrostatic field. Combined influence of the effective mass periodically varied in space and external electrostatic field on the electron transport leads to new undiscovered phenomena. We consider transport at the center of the Brillouin zone as well as offcenterzone transport. Results obtained open possibility for control of electron transport in semiconductor superlattices.
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20. photonics band gap, microstrip, filter Vestnik KhNU ¹883 Pages. 2024
In this paper, it is presented a twosided onedimensional photonic bandgap microstrip structure. The structure is obtained by etching a one periodic pattern of circles in the ground plane of a microstrip line and variation of the characteristic impedance as a function of the length of the microstrip line. The calculated scattering parameters of the proposed filter are presented.
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21. magnetocardiography, gradiometer, current dipole, sensitivity, Hessian Vestnik KhNU ¹883 Pages. 2529
The article considers hexagonal grid of gradiometer sensors of magnetic field. The aim of the study is to determine the optimal parameters of the grid and the gradiometers in order to obtain maximum sensitivity of the measuring system in terms of location of a pointwise dipole source of magnetic field in some spatial region. These parameters are the distance between adjacent gradiometers in the grid (base of the grid) and the distance between two coils within gradiometer (base of the gradiometer). The obtained results allowed us to formulate some recommendations regarding design of such magnetocardiographic measuring system.
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22. AlN, GaN, InN diodes, frequency transformation factor , drift velocity, harmonics. Vestnik KhNU ¹883 Pages. 3034
Multiplication of frequency at impact ionization in intervalley transfer electron diodes on basis InN, AlN is considered. The current – voltage characteristics of intervalley transfer electron diodes have negative conductivity region and strong increasing current regions due to impact ionization that is nonlinearity and lead to transparent frequency. If impact ionization takes place, frequency transformation factor increases and reaches, for example, 40 % for second harmonic have being showed. The frequency transformation factor increases for second and third harmonic if first harmonic voltage amplitude is several threshold voltage if compare with frequency transformation factor for all nitride compounds.
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23. time domain, artificial neural network, impulse fields, layered medium Vestnik KhNU ¹883 Pages. 3540
The problem of determination of thickness a layer of layered medium by impulse irradiation is solved. The impulse fields reflected from the layered medium with electrical characteristics close to the characteristics of human skin are analyzed by artificial neural network in time domain directly. The normal incidence of plane wave with Gaussian time form is considered. The reflected electromagnetic field is calculated by FDTD method. Initial data for the neural network analysis are the values of amplitude of electrical component of reflected field. As an example, the network is trained to determine the thickness of one of the layers of the medium. The stability of the determination in presence of interferences, experimental errors and instabilities of medium parameters is investigated.
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24. mode basis method, transient field, spherical modes, ring current. Vestnik KhNU ¹883 Pages. 4144
The convergence of spherical mode expansions in the time domain to the exact solution is shown on an example of a test problem that has a closedform solution. Radiation of a ring with transient current in free space is considered. It was shown that there exist only a finite number of propagating modes for any frequency at any given radius of a circumventing spherical surface. Thus within the framework of mode basis method in spherical coordinate system a finite number of main modes is sufficient to describe radiation of a transient sources located within a sphere of some given radius.
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25. layered media, dispersion, inverse problem, dielectric permittivity. Vestnik KhNU ¹883 Pages. 4549
In the present paper the problem of dielectric permittivity profile reconstruction with regard to dispersion is discussed. The nature of the dispersion function is assumed to be known and unknown functions are real and imaginary parts of dielectric permittivity. Frequency is used as an informative parameter. It is assumed that the layered medium is laying on a substrate with known dielectric permittivity and permeability. The iterative method reducing the problem of reconstruction to the functional minimization problem is used. Within the scope of this method the inverse problem for of dielectric permittivity profile with a conducting medium dispersion is solved. The algorithm and numerical results are given.
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26. Vestnik KhNU ¹883 Pages. 5053
A new method based on integral equation formulation is proposed for construction of mode basis in open dielectric waveguides. Decomposition of the spectrum in such structures into discrete (surface wave) and continuous (volume wave) part is analyzed. Dispersion equation for modes of the discrete spectrum and analytical formulae for calculation of mode functions of the discrete and continuous spectrum have been found. The examples of the discrete and continuous spectrum mode function are shown. Orthogonality of the mode function is demonstrated analytically. The expression for norm function has been found in a closed form.
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27. diffraction electromagnetic waves, chiral structure, polarization properties on frequency Vestnik KhNU ¹883 Pages. 5458
In given paper the diffraction of electromagnetic waves on volume grid is investigated experimentally. The grid consists of rectangular elements. Two planes of twodimensional periodic rectangular metallic string elements located on both dielectric surfaces and connected by cylindrical conductors. The measurements of dependence of grid transmission index on frequency and polarization are carried out. The measurements were made in frequency range 2638,8 GHz. The grid was irradiated by quasiplane wave with incident on the normal to the surface of the grid.
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28. slot, microwaves, waveguide, dielectric, admittance, scattering parameters Vestnik KhNU ¹883 Pages. 5966
The problem of a longitudinal slot radiation is cut in wide wall of rectangular waveguide with threelayer dielectric filling which parallel to wide wall of a waveguide was solved. The excitation problem is solved with modified eigen waves method. As eigen waves of the LM and LE modes are chosen. The field in the source region includes the potential functions as well. The scattering parameters and resonance properties of slot are investigated. The scattering parameters calculated are in a good agreement with experimental data.
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29. spurious resonance, a branching of the waveguides, matching uniformity, connection area, system of the linear algebraic equations. Vestnik KhNU ¹883 Pages. 6772
In work it is shown, that the problem of existence of spurious resonances in problems of diffraction waveguide waves on various discontinue in waveguides is connected with incorrect representation of matrix elements of system of the linear algebraic equations (SLAE) which lead to features at their numerical decision. On an example of a problem of diffraction waveguide waves on the Òbranching of rectangular wave guides it is shown, that spurious resonances correspond to resonances of area of connection of waveguides. This computing mistake can be rather simply corrected due to correct representation of matrix elements SLAE which has no features. Results of calculations have shown efficiency of such approach for the decision of problems on own oscillations and problems of diffraction on the Òbranching of hollow wave guides, and tees with dielectric and ferrite resonators in the field of connection of waveguides.
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30. Compromising emanations: overview and system analysis N.N. Gorobets, A.V. Trivaylo compromising emanations, nearfieldzone, electromagnetic, radiation, time domain Vestnik KhNU ¹883 Pages. 8388
The problem of compromising radiation of spurious signals in the near, intermediate and far zones of observation in time domain are considered. The Compromising emanation system analysis for finding spurious radiation is proposed. The goal of the given approach is to speed the development of technical protection of information. In approximation of the given current distribution it has been suggested a solution considering the influence of the nearfield effects upon directional characteristics of spurious signals radiation. The application of the new method allows us to investigate compromising of technical means in time and frequency domain.
Download >>
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