1. Complex dielectric permittivity of disperse heterogeneous systems and their components
L.M. Atroshenko, N.N. Gorobets, L.P. Safronova
complex dielectric permittivity, Disperse system
Vestnik KhNU ¹712 Pages. 8-16
The relationship between complex dielectric permittivity of two-component disperse system, its components' volume shares and dielectric permittivity has been obtained. The method for computation of volume shares and dielectric permittivity of water solution hydrated inclusions is suggested
2. Method of finding permittivity, volume characteristics and hydratation of components of water solutions
L.M. Atroshenko, N.N. Gorobets, L.P. Safronova
Dielectric permittivity, bound water, hydration, specific volume, Density
Vestnik KhNU ¹712 Pages. 17-20
A method for calculation of permittivity of bound water, hydration of substances, volume shares and specific volumes of water solution components, based on data of measurements of the complex permittivity and solution densities, was suggested
3. Multifunctional measuring platform for investigations parameters of metal-dielectric structures
V.A. Katrich, D.V. Mayboroda, S.A. Pogarsky, I.I. Saprykin
automation complex, Dielectric image guide, energetic characteristics
Vestnik KhNU ¹712 Pages. 21-24
The multifunctional automation measuring platform for ultra high frequencies parameters definition has been de- signed. The basis of this complex is the controlled mechanical platform which allows to measure the field amplitudes along two orthogonal coordinates. The processing of measuring date realizes with the help of special software. The measuring of energetic characteristics of radiating module based on dielectric image guide has been carried out
4. Scattering electromagnetic waves by coupling aperture of electrodynamic volumes in presence of finite sizes impedance body
impedance vibrator, narrow slot, Distributed surface impedance, rectangular waveguide
Vestnik KhNU ¹712 Pages. 47-51
Systems of integral-differential equations concerning surface equivalent magnetic and electrical currents which are excited with impressed sources of electromagnetic field in the coupling aperture of electrodynamic volumes and in the finite sizes impedance body have been obtained. The approximate analytical solution of the equations system for the narrow transverse slot in the broad wall of rectangular waveguide with the thin impedance vibrator was represented. Also theoretical and experimental graphs of electrodynamic characteristics of such structure in dependence on the wavelength in the base oscillations band the waveguide was represented
5. Application of the digital holographic interference microscope for investigation of human red blood cells 3-D morphology
T.V. Tishko, V.P. Titar, D.N. Tishko
Digital holographic interference microscope, erythrocyte, morphology, sphericity coefficient, Diagnostics, micro-object
Vestnik KhNU ¹712 Pages. 52-55
Results on the digital holographic interference microscope for 3-D imaging of native blood erythrocytes are presented. Blood samples of healthy people and patients with different pathologies were used. Three basic morphology kinds of blood erythrocytes were detected. A sphericity coefficient was used as quantitative characteristics of blood erythrocytes morphology. It is shown that, blood erythrocytes 3-D morphology is very important diagnostics characteristics in medical practice. The digital holographic interference microscope is an effective device for the purposes of medical diagnostics
6. Radiation from dual-mode circular waveguide excited by dominant and higher-order modes simultaneously
A.V. Shishkova, N.N. Gorobets
microwaves, multimode waveguide, Diffraction, higher-order modes, Weinstein rigorous technique, Wiener-Hopf technique, radiation pattern.
Vestnik KhNU ¹712 Pages. 56-61
On the basis of Weinstein rigorous solution to the problem of electromagnetic mode diffraction at an open-ended circular waveguide the characteristics of radiation from multimode waveguides excited by H11 dominant mode and. higher-order modes (E01, and H01) simultaneously are calculated and analyzed. The calculation of radiation from waveguide with dual- mode excitation is carried out in the whole observation space and in wide frequency bandwidth, taking into account the higher-order mode transformation and currents leaking on the external surface of a waveguide.
7. Absorption of electromagnetic energy of dipole antenna of double layer dielectric sphere
wave absorption, Double layer dielectric sphere, perfectly conducting spherical screen, radial dielectric dipole, Dual series equations, method of analytical regularization
Vestnik KhNU ¹712 Pages. 62-66
Considered the problem of electromagnetic energy absorption by double layer sphere, which the simplified model of human head protected by the helmet with the dipole antenna. This investigation is interesting due to control of energy absorption in sensible parts of human head tissues. The problem is solved by method analytical regularization, which reduces the problem to the system of linear equations of Fredholm second kind which provides guaranteed convergence. Basic absorption characteristics are obtained and comparison of protection effectiveness for different sizes helmets are made
8. The influence of the inner chanal of a periodic iris-loaded circular waveguide concerning its eigenmode mutual transformations
He Shi, S.K. Katenev, S.N. Shulga
Dispersion, Brillouin diagram, mode transformation
Vestnik KhNU ¹712 Pages. 80-83
The mutual eigenmode transformations are considered of a periodic iris-loaded circular waveguide against variations or its inner radius, using BriUouin diagram characteristics. The specific features of the waveguide regular and periodicity modes of Eo,and asymmetric waves are pointed out
9. Analytical solutions in time domain for electromagnetic fields in a cavity with Debye medium
Dielectric, Dispersion, Debye medium, electromagnetic fields in a cavity with a dielectric, evolutionary approach to electromagnetics, time domain
Vestnik KhNU ¹712 Pages. 84-90
The theoretical investigation of the properties of electromagnetic oscillations in a cavity with Debye medium is carried out. The problem is considered within the frame of the Analytical Approach to Electromagnetics in the Time Domain (TD), which allows obtaining closed-form solutions in TD for a wide range of electrodynamical problems. For the description of electromagnetic properties of the medium is used representation of the constitutive relation in an integral form. The analytical solutions are obtained for the several excited functions in TD and they validity conditions are defined. Characteristics of electromagnetic oscillations are presented for different relaxation time and dielectric susceptibility
10. Electromagnetic wave detraction on a resistive unclosed cone
V.A. Doroshenko, O.G. Litvinova
Diffraction, resistive, longitudinal slots, an integral transform, analytical solutions
Vestnik KhNU ¹712 Pages. 95-99
Problem of harmonic electromagnetic wave diffraction on a resistive cone with longitudinal slots is considered. The boundary problem solution uses the Kontorovich-Lebedev integral transform and a semi-inversion method. Analytical solutions are obtained for the cone with a lot of narrow slots and reactive impedance. Impedance and longitudinal slots effects on scattering field structure is studied
11. On the directive gain of the self-focusing antenna
Directive gain, self-focusing antenna, inhomogeneities, structure function
Vestnik KhNU ¹756 Pages. 11-17
The influence of the atmospheric inhomogeneities on the directive gain of the self-focusing antenna array (SFAA) at description of the atmosphere by the theory of the local-isotropic turbulence is considered. There are analyzed two cases when a size of the SFAA subaperture is respectively more or less than the turbulence scale of the medium. It is shown mat the results of the meat directive gain estimation for the two cases are well conformed qualitatively with the analogous estimates obtained at the atmosphere description wife the help of the Gaussian correlation function of its refractivity index
12. One-dipole inverse problem of magnetostatics for reconstruction of heart-torso electric activity from magnetocardiography measurements
Bagatskaya O., Butrym A., Durneva Yu., Shulga S.
Do not determinated
Vestnik KhNU ¹756 Pages. 47-50
Do not determinated
13. INFLUENCE of ENVIRONMENT ON the FIELD, SCATTERING ON the LATTICE WITH LAYER, AT ANY FALL of the WAVE
A.I. Adonina, V.B. Khokh
lattice, environment, Dielectric, a stream of capacity, method of Riman-Hilbert problem
Vestnik KhNU ¹756 Pages. 51-56
The decision of a task in view is carried out for Å and Í the fields appropriate to two subsystems on which the system of the equations of the Maxwell for environments is divided. Integrated characteristics of a field are determined from the decision of systems of the linear algebraic equations received by a method of method of Riman-Hilbert problem , for a case when the smallest parameter decreases in inverse proportion to a square n->infinity. Programs (fort) with construction of diagrams are made. The analysis of the diagrams in part given in work, allows to establish influence of parameters of structure and corners of fall of a wave on anomalies in an absent-minded field for each concrete case
14. DESTRUCTION OF PULSE TRAINS IN WEAKLY NONLINEAR OSCILLATOR
chaos, Dynamical systems, train pulses, quasi linear oscillator
Vestnik KhNU ¹756 Pages. 71-78
A study has been carried out on the transition of train of pulses via a weakly nonlinear oscillator. Conditions of destruction of such trains as a result of appearance of chaotic instabilities have been analyzed. Analytically conditions of the appearance of chaotic instabilities have been determined by using the method of secondary averaging.
15. GAUSSIAN EXPANSIONS FOR RADIATION PATTERN OF AN OPEN-ENDED LINE WITH IMPEDANCE BORDERS
aperture distribution, impedance border, orthogonal functions, Diffraction integral, feed
Vestnik KhNU ¹756 Pages. 87-90
Near-field and far-field two-parameter expansions in terms of Laguerre-Gaussian orthogonal basis functions are proposed, which take into account the effect of impedance feed borders. The expansions enable the feed characteristics on a base of lines with impedance borders to be calculated in wide frequency region. Radiation intensity distributions for the open-ended two-layer metal-shielded dielectric waveguide in a nonresonance regions of surface impedance varying, relative errors of expansion truncations, comparison with experimental data are presented
16. Al0,3Ga0,7As/GaAs cathode transfer electron diode's efficiency
O.V. Botsula Prokhorov E.D, A.V. Dydchenko
Doping, cathode contact, tunnelling, negative differential conductivity, oscillation efficiency
Vestnik KhNU ¹756 Pages. 97-100
The results of analyse efficiency of GaAs/ Al0,3Ga0,7As/GaAs GaAs/ Al0,3Ga0,7As/GaAs / GaAs cathode transfer electron diode are present. The space charge model are used. There are two region of negative differential conductivity of current - voltage characteristic are shown . The condition lead to oscillation due both region and oscillation efficiency have been determined.
17. Influence of impact ionization on efficiency of rsca-diodes operation on basis of InN, GaN, AIN
D.V. Pavlenko, E.D. Prokhorov
nitrides, RSCA oscillators, oscillating efficiency, Drift velocity
Vestnik KhNU ¹756 Pages. 109-112
The impact ionisation in RSCA diodes is considered on the basis of nitrides InN, GaN, AIN. Possible overvoltage on diodes and possible efficiency of generation are analyzed. It is shown, that at development of a impact ionisation in RSCA diodes in correspondence with the diffusion theory the considered materials are perspective for RSCA diodes for operation in centimeter and millimeter wavebands (voltage over threshold 3 ... 5 at efficiency up to 11 ... 13 %)
18. THE H10 WAVE SCATTARING BY THE THIN VARIABLE RADIUS IMPEDANCE VIBRATOR IN A
Nesterenko, E.Y. Belogurov, V.A. Katrich, V.I Kijko
impedance vibrator, biconical vibrator, Distributed surface impedance, rectangular waveguide, the method of induced electromotive forces
Vestnik KhNU ¹806 Pages. 14-17
The problem of the fundamental wave scattering by the thin variable radius impedance vibrator arbitrary situated in a rectangular waveguide was solved. Calculations were carried out and energetic characteristics of such structures were plotted
19. Resonance phenomena occurring as a thin refractive cylinder diffracts the hertzian wave
Yu. I. Grebenyuk, N. G. Kokodiy, Khe Shi
Diffraction, thin cylinder, refractive index, scattering, absorption, weakening, resonance
Vestnik KhNU ¹806 Pages. 33-39
On the basis of solutions to the wave equation, the efficiency of dispersing, absorbing, and weakening the electromagnetic field that a thin cylinder with a large refractive index diffracts has been estimated. The transverse and longitudinal distribution of the electromagnetic field inside and outside of the cylinder has been calculated. The resonance is found to increase the intensity of both the electromagnetic wave field inside the cylinder and the scattered wave outside. Inside the cylinder at resonance, a wave propagating along its surface arises, and under some conditions, a wave propagating through the cylinder is also generated. As the refractive index is increased, the wave tracks the cylinder surface more closely, and its intensity is progressively enhanced.
20. The influence of a dispersion and losses to the interaction of impulse signal with the model of the biological tissues
O.N. Zheryobkina, O.V. Kazanskiy
impulse signal, a biological tissue, time domain, flatlayer dielectric, Dispersion
Vestnik KhNU ¹806 Pages. 40-43
In this paper the interaction of the impulse signal with biological tissues on an example of the flatlayer dielectric that models consecutive layers a skin, fat, muscle tissue is investigated. In this model, it is taken into account dispersion of the dielectric permeability and losses in a medium. The calculation program is received in result. It accounts the space-time characteristics of the reflected and past signals for layers of the flatlayer dielectric with parameters of biological tissues. Influence of values of the dielectric permeability and angle of incidence on the characteristics of past and scattered signals also is considered.
21. Thermo equilibrium and differential capacity of p+-n junction
p+- n junction, Distribution of potential
Vestnik KhNU ¹806 Pages. 48-53
The accurate distribution of field and potential in the region of abrupt p+- n junction under thermodynamic equilibrium is obtaned. The formula of p+- n junction width with any relation of mobile charge carrier magnitude and ion donors of n-region is obtained. The dependence of p+- n junction differential capacity upon out voltage, which does not need numerary methods is obtained. It was shown, that under direct and reverse switching of p+- n junction the dependence of capacity upon voltage is more complicated than for p- n junction in the depletion mode.
22. Thermo equilibrium state of p+-p junction
p+-p junction, Distribution of potential
Vestnik KhNU ¹806 Pages. 54-58
The thermo equilibrium state of p+-p junction with surface charge of p+-region was investigated. The distribution of field and potential in the region of such junction is describing by Poisson's equation with un-known charge distribution on coordinate. The solution method of this equation allowing to obtain precise distribution of field and potential on coordinate was proposed. The formula for width of p+-p junction with any ratio of mobile charge carriers and charge of ion-acceptors in p-region was obtained.
23. HARMONIC GENERATION BY IMPACT IONIZATION IN CaN LSA DIOD
O.V. Botsula, D.V. Pavlenko, E.D. Prokhorov
LSA diodes, generation efficiency, nitrides, Drift velocity, harmonics
Vestnik KhNU ¹806 Pages. 65-69
In this work an impact ionization in LSA diodes on basis of GaN is considered. Analytical calculation of typical times of passing of a number of the physical processes determining properties of the oscillator, and limitings imposed by them on frequency properties of the diode is submitted. It is shown, that at developing impact ionization in LSA diodes, according to the diffusive theory, the considered compounds are perspective for manufacturing LSA diodes for work in sm and mm - ranges (electrical pressure over threshold 3 … 5 times, at an efficiency up to 11 … 13 %). The results of calculation of efficiency of oscillators on basis of GaN LSA diodes are given at their work in modes on a base frequency and at a harmonic generation.
24. Spatial and temporal features of the midlatitude total electron content
I. G. Zakharov
total electron content, Dual-frequency Doppler shift measurements, planetary waves
Vestnik KhNU ¹806 Pages. 82-86
Experimental study of the latitudinal and diurnal variations in the total electron content over Eastern Europe are present. The dual-frequency Doppler shift measurements from navigation satellites and incoherent scatter radar (ISR) data are used The ISR data were collected near Kharkiv city (49.6oN, 36.6oE), and the dual-frequency signals from navigation satellites in circular polar orbits at the altitude of about 1000 km were received at the Kharkiv V. Karazin National University Radiophysical Observatory (49.6oN, 36.3oE). The calculated total electron content maps span the 35o – 65oN geographic latitude range and the 24-hour local time range. These maps and other data represent all known features of diurnal and latitudinal total electron content variations at middle and subauroral latitudes, and in particular, they represent the local latitudinal maximum at 50oN geographic latitude in total electron content. The results obtained also indicate that tidal and planetary-scale waves act to noticeably modify the temporal and spatial variability of TEC, including that under quiet conditions.
25. Application of the digital holographic interference microscope for investigation of thin films
D.N. Tishko, T.V. Tishko, V.P.Titar, Yu. A. Zadneprovskiy, A.S. Kuprin, I.A.Zgoda
Digital holographic interference microscope, three-dimensional images, vacuum-arc method, thin AlN films
Vestnik KhNU ¹806 Pages. 99-102
For the first time the digital holographic interference microscope (DHIM) was used for investigation of thin films on transparent substrates. Three-dimensional images of AlN of thin films, deposited on acryl substrates by the vacuum-arc method have been obtained, their thicknesses have been measured. It has been shown that the DHIM can be successfully used for film surface quality checking, thickness and film damages parameters measurement.
26. Dispersive characteristics of magnetoplasma waves in the rectangular wave guide with InSb
O.A. Zamuraev, O.O. Puzanov, A.S. Tishchenko
magneto-plasma wave, semiconductor plasma, Dispersive characteristics, nitric temperature
Vestnik KhNU ¹834 Pages. 3-7
Frequency dependence of characteristics of magnetoplasma waves in the rectangular wave guide, containing longitudinal and cross-section - magnetized the semiconductor at various sizes of an induction of a magnetic field is experimentally investigated. Areas of values of an induction in which the behavior of wave number and factor of attenuation has resonant character are determined. An existence of two superficial magnetoplasma waves which are distributed in opposite directions is experimentally confirmed in longitudinal - magnetized semiconductor plasma. Good concurrence of results of experiment and numerical calculations is shown
27. Subterahertz diffraction radiation on the BWO frequency harmonics in the parametrical two-regimes electron device
E.N.Odarenko, A.A.Shmat’ko, P.V. Yudintcev
Diffraction radiation, Smith-Purcell effect, subterahertz waves, beam-wave interaction, nonlinear processes
Vestnik KhNU ¹834 Pages. 13-17
Diffraction radiation nonlinear theory that takes into account two-regimes interaction – self-consistent regimes of the BWO and GDI on the BWO frequency harmonics is developed. The existence of the BWO generation regime on the first harmonic and parametric type diffraction radiation amplification regime on the BWO frequency harmonics is shown on the base of the self-consistent equations set numerical solution. Ranges of the task parameters values that correspond to two-regimes interaction are defined
28. Electromagnetic waves focusing inside dielectric cylinder
N. N. Gorobets, N. N. Stasjuk
microwaves, Dielectric cylinder, plane wave, focusing points
Vestnik KhNU ¹834 Pages. 77-84
Computation and analysis of electrical and magnetic field amplitudes at focusing points inside dissipative dielectric cylinder illuminated by plane linear polarized wave have been performed using the approximation of geometric optics. It was shown that in the focal region fields vary according to oscillating law and field longitudinal gradients the more cylinder diameter and dielectric permittivity, the large at that. Results of investigation allow to explain subthreshold (nonthermal) exposure of millimeter and submillimeter electromagnetic waves on human and other biological objects
29. Directivity characteristics of rarefied antenna arrays
N.N. Gorobets, A.A. Bulgakova
electromagnetic waves, antennas, antenna array, Directivity characteristics
Vestnik KhNU ¹834 Pages. 89-94
The radiation pattern, directive gain and scattering coefficient of equivedistance linear array were calculated and their dependencies on the number of radiators and distances between them were analyzed. It is shown that for every number of radiators the optimal antenna length of L≈0,9(N-1), allowing to obtain the maximum of directive gain, occurs. For greater antenna length or increase in operating frequency, directive gain varies according to oscillating dependencies. The greater number of radiators occurs, the greater difference of maximums and minimums occurs. For small number of radiators (N≤8), the directivity characteristics of the array is higher, then for continuous antennas of the same electrical length. For N≥16, their characteristics coincide
30. Frequency multiplication at impact ionization in GaN-diodes
Î. V. Botsula, D. V. Pavlenko, E. D. Prokhorov
the GaN diode, coefficient conversion transducing, Drift velocity, harmonics
Vestnik KhNU ¹834 Pages. 100-103
The frequency multiplication at impact ionization in transfer electron GaN diodes nave been considered. The coefficient conversion transducing increase if impact ionization in GaN diodes takes place have been demonstrated. For example, coefficient conversion transducing in second harmonic arrive at 40 %.
31. Global Sensitivity analysis of the dipole matrix element according to variation of parameters of the indium surface segregation in ingan/gan quantum well
indium surface segregation, semiconductor nitrides, piezoelectric polarization, Dipole matrix element, global sensitivity analysis
Vestnik KhNU ¹853 Pages. 8-14
In this paper, influence of the indium surface segregation on dipole matrix element for InGaN/GaN heterostructure is under investigation. The global sensitivity analysis has been applied for quantitative estimation of the indium surface segregation effect at each interface of the quantum well. Together with the indium surface segregation, the piezoelectric effects are considered. It has been shown that joint action of the piezoelectric fields and the indium surface segregation leads to changes in the selection rules for optical transitions. Results give the method to apply the optical spectroscopy for observation of the indium surface segregation
32. Oscillation efficiency of TED diodes on the basis of nitrides
E. D. Prokhorov, O. V. Botsula, A. N. Zabazhan
AlN, GaN, InN-diodes, Drift speed, oscillation efficiency
Vestnik KhNU ¹853 Pages. 15-21
Oscillation efficiency of intervalley transfer electrons diodes on the basis of nitrides (InN, GaN, AlN) is considered. Electric fields at peak oscillation efficiency are determined. The results have been compared to results for GaAs. The account of floatable potential in connections InGaN improves their power characteristics in comparison with power characteristics of these connections without taking into account floatable potential, maximal efficiency In0.8 Ga 0.2 sub>N and In0.5Ga0.5N diodes to compare to InN diodes on 30 % is higher (22 % to compare to 16,43 %) but at more high tensions of an electric field. The maximal oscillation efficiency is observed at higher electric fields than GaAs ( from 250 êV/sm for InN to 1000 kV/sm for AlN)
33. Inner partial mutual admittance of two overlopping longitudinal slots in a rectangular waveguide with dielectric layer parallel to narrow walls
A.A.Lyakhovsky, L.P.Yatsuk, A.F.Lyakhovsky
, layer, Dielectric, slot, admittance, scattering parameters
Vestnik KhNU ¹853 Pages. 22-27
The expression for the partial inner mutual admittance of two longitudinal slots overlapping along waveguide longitudinal axis is obtained. The slots are cut in a broad wall of a rectangular waveguide filled with three-layered dielectric. The excitation problem is solved with the modified eigen waves method. As eigen waves of the LE and LM modes are chosen. The field in the source region includes the potential functions as well. Dependences of inner mutual admittance and scattering parameters on distance between two slots and frequency are investigated. The system scattering parameters calculated are in a good agreement with experimental data
34. Algorithms of the processing signal from the trellised receiver for measuring of the laser radiation characteristics
Kokodiy N.G., Pak A.O.
the laser, optical radiation, intensity, bolometer, Direct task, reverse task
Vestnik KhNU ¹853 Pages. 37-44
In this paper has been considered the development of the device for the measurement of the intensity distribution in the beam of optical radiation. The algorithm of processing of a signal from the receiver of radiation is studied. The method of measurement of the intensity distribution of optical radiation by the bolometric grid is offered. The developed algorithms for processing a signal from the measuring converter and programs realizing them are checked up experimentally, their serviceability is confirmed. The comparative characteristic of algorithms based on the transformation of Fourier and transformation of Radon has shown an opportunity of their use in practice
35. Asymptotic method of the solution of diffraction problem on the convex impedance cylinder, excited by the string of the electric current
V.I. Vyunnik, A.A, Zvyagintsev
Diffraction, asymptotic method, interpolation, convex impedance cilinder
Vestnik KhNU ¹853 Pages. 64-70
In the work considered the problem of diffraction electromagnetic waves on the convex impedance cylinder exited by string of the electric current, located near to its surface. The method asymptotic theories of the diffraction, offered by Fok is used. Are received asymptotic interpolation formulas for calculation radar cross section of the system string the current - cylinder, for a case of circular and elliptic impedance cylinders. The received formulas are suitable for calculations both in shadow and in lighted areas. It is shown, that these formulas can be distributed on a case of the any convex impedance cylinder with variable curvature
36. Algorithm of a pulse signals delay definition, based on a Hilbert's transformation
D.O. Batrakov, D.V.Golovin, S.V. Grekov, A.G. Batrakova*
pulse signals, Definition of a delay of signals, Hilbert's transformation, plane-layered media, thickness measurements
Vestnik KhNU ¹853 Pages. 71-76
In the present paper the algorithm of processing of the pulse signals reflected from plane-layered media is offered. It is supposed, that an effective thickness of layers less than spatial size of an impulse. This feature of a problem complicates use earlier proposed methods of signals time delay evaluating. Therefore in paper the theoretical analysis of possibilities of various approaches for processing of signals is carried out and the algorithm and the corresponding software for definition not only a time delay, but also physical and geometrical characteristics of investigated objects are offered. Results of numerical modelling and experimental researches for the purpose of definition of sensitivity and resolution of a method, and also possibility of its practical use are given
37. HF ionosonde signal focusing by traveling ionospheric disturbances
Yu. B. Milovanov, V. F. Pushin, O. F. Tyrnov
traveling ionospheric disturbances, signal amplitude variations, Doppler frequency shift, focusing factor, computer simulation
Vestnik KhNU ¹853 Pages. 88-94
HF signal focusing due to linear and nonlinear wave disturbances occurring during monostatic ionospheric sounding is discussed. A technique is developed for estimating signal amplitude variation due to focusing based on beating amplitude measurements during significant Doppler frequency shift events. The intercomparison of measured and modeled variations in beating amplitudes, the focusing index, and Doppler frequency shift show a qualitative agreement. The simultaneous analysis of variations in the beating amplitude and the Doppler frequency shift makes the interpretation of measurements more definite, e.g., it permits the isolation of large scale disturbances traveling at approximately 1 km/s
38. 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. 30-34
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
39. Longitudinal slot in a rectangular waveguide with dielectric layer parallel to wide walls
slot, microwaves, waveguide, Dielectric, admittance, scattering parameters.
Vestnik KhNU ¹883 Pages. 59-66
The longitudinal slot is cut in wide wall of rectangular waveguide with three-layer 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
40. Dielectric permittivity profile reconstruction by frequency probing problem for a plane-layered media with regard to dispersion
Batrakov D.O., Simachov O.A.
plane layered media, Dispersion, inverse problem, Dielectric permittivity
Vestnik KhNU ¹883 Pages. 45-49
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
41. Ðåøåò÷àòûé ïðèåìíèê äëÿ èçìåðåíèé õàðàêòåðèñòèê ëàçåðíîãî èçëó÷åíèÿ
Lizogubenko S.V., Kokodiy N.G.
scattering pattern, Diameter of the particles, scattering, brightness of the light spot, beam intensity
Vestnik KhNU ¹966 Pages. 9-12
Considered the method of defining the size of microparticles using a digitized image of the scattering. For research the optical method is used It consists that the researched substance, consisting of microparticles, is illuminated with the beam of optical radiation and then the scattering of the transmitted light is registered. After this, the digital processing of resulting scattering pattern is carried out and held the measurement of particle size in two different ways.
42. Signal scattering on the meteor trail
signal scattering, meteor trail, Diffraction oscillations, electron density, plasma collective interaction, impulse response.
Vestnik KhNU ¹966 Pages. 90-96
A generalized model of the radiosignal scattering on the meteor trail is proposed. The model allows to take into account the process of formation and development of the meteor trail, and to calculate the scattered signal power change without sharing the meteor trails on underdense and overdense. As input parameters of the model used the physical parameters of the meteoroid - the mass and velocity, which determine the ionization of the plasma formation, as well as the location and orientation of the meteor trail. In the derivation of the analytical relations taken into account the presence of the plasma sheath surrounding the 'metal cylinder' and the collective interactions in the plasma. In the paper shown that the results of calculations are in good agreement with observations.
43. Influence of shading of the radiating aperture of single-reflector antenna by focal module on directional characteristics
Gorobets N.N., Kiyko V.I.
microwaves, reflector antennas, reflector shading, Directional characteristics
Vestnik KhNU ¹966 Pages. 97-102
The effect of shading of the radiating aperture single-reflector parabolic antenna on radiation pattern, gain, wide beamwidth and sidelobe levels while changing the focal length of the relationship to the diameter of the reflector in the range of 0.5 to 1.5 takes place was theoretically investigated. Thus, it was shown that the effect of shading on all directional characteristics is the less than the longer-focused is the reflector. The minimum level of side lobes is in the case of short-focused reflector
radioholography, multiposition spatially-coherent system, Dynamic conflict situation
Vestnik KhNU ¹966 Pages. 72-76
Possibility of creation of the radioholographic informative system is shown for the decision of problem tasks of modern and perspective radio-location and construction on its example of system theory of radio-location. The decision of problem tasks of radio-location brings a necessity over to determination of ways of its development, and a necessity of decision of basic problem task of radio-location systems engineering is developments system the theory of radio-location - results in determination of ways of development of formal language for description of the state and conduct of the difficult system. They, in same queue, result in the necessity of increase of system indexes of quality of the system, especially at the supervision of stream of objects in the conditions of strong counteraction, and to the necessity of creation of the most informative system of new generation. The technical look of such system is examined.
AlN, GaN, InN diodes, frequency transformation factor , Drift velocity, harmonics.
Vestnik KhNU ¹883 Pages. 30-34
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.
layered media, Dispersion, inverse problem, Dielectric permittivity.
Vestnik KhNU ¹883 Pages. 45-49
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.
Diffraction electromagnetic waves, chiral structure, polarization properties on frequency
Vestnik KhNU ¹883 Pages. 54-58
In given paper the diffraction of electromagnetic waves on volume grid is investigated experimentally. The grid consists of rectangular elements. Two planes of two-dimensional 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 26-38,8 GHz. The grid was irradiated by quasi-plane wave with incident on the normal to the surface of the grid.
slot, microwaves, waveguide, Dielectric, admittance, scattering parameters
Vestnik KhNU ¹883 Pages. 59-66
The problem of a longitudinal slot radiation is cut in wide wall of rectangular waveguide with three-layer 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.
antenna array, horizontal polarization, Double slots, slowing system.
Vestnik KhNU ¹927 Pages. 54-58
Energetic and directional characteristics of an antenna array (AA) with single transversal slots and double ones cut in a rectangular waveguide, partially filled with dielectric are investigated. In the case of single transversal slots and double transversal slots a dielectric layer is parallel to broad walls of the waveguide. It was shown the possibility to construct an AA with double transversal slots having the pattern without diffraction lobes and high level of radiation power in the wide frequency band.
slot, waveguide, Dielectric, admittance, scattering parameters, slot-waveguide array.
Vestnik KhNU ¹927 Pages. 59-64
The scattering problem of a longitudinal slot system is cut in wide wall of rectangular waveguide with three-layer dielectric filling which parallel to wide wall of a waveguide was solved. The scattering parameters and gain of linear slotted-waveguide array are investigated in range of frequency. The gain optimization and synthesis of linear slotted-waveguide array were carried out using a genetic algorithm. The obtained gain weakly depends from frequency.
GaAs diodes, Drift speed, lag, coefficient frequency conversion, maximum frequencies.
Vestnik KhNU ¹927 Pages. 11-14
Coefficient frequency conversion (KFC) diodes with intervalley transfer of electrons based on GaAs in a wide range of frequencies is investigated. It is shown that the threshold voltages of the KFC in mobility 8000 sm2/(V·s) (GaAs) more than the KFC in 1000 sm2/(V·s) mobility (without NDC) in 5 times. At the further increase voltages in the mobility ratio of KFC 8000 sm2/(V·s) to KFC for 1000 sm2/(V·s) mobility decreases (at 10 - 12 kV/cm is about 2, at 20 - 30 kV/cm ratio KFC close to unity). Take into account the inertia of the redistribution of electrons between the valleys of the conduction band of GaAs. It is shown that the transformation frequency conductivity GaAs diodes is possible at frequencies exceeding the maximum frequency of generation in the diode mode of a uniform field.
plane dielectric waveguide, inverted dielectric waveguide, Fourier transformation, Fredholm integral equation, Dispersion equation.
Vestnik KhNU ¹927 Pages. 78-84
The eigenvawes problem of inverted dielectric waveguide is considered. The cross-section of waveguide is divided into partial domains in such way that the field in each domain is represented as a superposition of eigenwaves of a plane dielectric waveguide. Using the equality conditions of tangential components of electric and magnetic fields at the interface of domains two Fredholm integral equations of the second kind relatively waves amplitudes are obtained. The symmetric and asymmetric waves are considered. The dependencies of the propagation constant versus wave number and field distribution in the waveguide are presented.
wavelet-analysis, continuous wavelet transform, Dynamic energogram, space radio physics, powerful non-stationary disturbance sources.
Vestnik KhNU ¹927 Pages. 96-102
Development and improvement of methods of time-frequency analysis of signals with continuous wavelet transform usage were proposed. The new method consists in the simultaneous analysis of wavelet spectrum and dynamic energograms of the continuous wavelet transform. Using the example of analysis of real non-stationary, non-linear and ultra wideband signals and processes in space radio physics problems, in particular, using the analysis of effects, caused by the powerful, non-stationary action, the dynamic energogram method effectiveness was shown.
laser, optical radiation, intensity, Distribution, receiver, Direct problem, inverse problem.
Vestnik KhNU ¹927 Pages. 31-35
In this paper has been considered the method of the measurement of the intensity distribution in the beam of optical radiation and the algorithm of processing of a signal from the receiver. The method is using the knife attenuator of the special shape. The power of the reflected radiation on knife was measured by using detector of photoelectric. The algorithm and program for handling of the signal from receiver are developed. The influence of errors in the measurement signal from the receiver on the results of calculations has been researched. The experiment has confirmed the serviceability of the method and the possible of their use in practice.
DKDP single crystals, Dc electrical conductivity, concentration of L-defects, gamma -irradiation, first order kinetics.
Vestnik KhNU ¹927 Pages. 22-30
The dependence of electrical dc conductivity of KD2PO4 (DKDP) single crystals on the dose of ?-irradiation is investigated. The conductivity is found to decrease exponentially in a dosage range of 3.0 102÷2.8 104 Gy. The temperature dependences of the conductivity are described by the exponential law. The pre-exponential factor and activation energy values of conductivity are determined for the crystals irradiated with various doses. Analysis of the dose and temperature dependences shows that the radiation-induced decrease of the conductivity is associated with the decrease of L-defect concentration in the crystal. The concentration changes in accordance with the law of first order kinetics. Possible mechanisms of the L-defect concentration changes under gamma -irradiation of crystals are discussed.
founded: 55 result (s)