Kharkov National University
V.N.Karazin
Main / Vestnik KhNU /Radiophysics and Electronics
 
Main
 
Edit. Board
 
For authors
 
Numbers
 
Authors
 
Titles
 
Keywords
 

1.  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 712 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



2.  Radiation of electromagnetic waves by the system of transverse and longitudinal slots in the wide wall of rectangular waveguide
S.L. Berdnik
antenna array, multi-frequency antenna, Slot system, multimode rectangular waveguide
Vestnik KhNU 712 Pages. 25-29

The problem of radiation of electromagnetic waves by the double-frequency multielement slot array on a multimode waveguide was solved by the Galerkin's method. The radiating aperture is two systems of longitudinal and transverse slots in the wide wall of the rectangular waveguide. The power and directional characteristics of such structure were investigated. Thickness of the waveguide wall, interior and exterior interactions between slots were taken into account at calculations



3.  Stochastic fields optimal processing in MPSAR
A.V. Ksendzuk
multiposition system, Synthetic aperture, Stochastic model, combined estimation
Vestnik KhNU 712 Pages. 30-32

This paper represents optimal combined estimation algorithm in multiposition synthetic aperture radar as- signed for estimation of the parameters, contained in correlation function of the complex scattering coefficient; the most important special cases were presented



4.  Telemetering methods, devices and their application in vertebrology
S.N. Kulish, O.Y. Kagan
radiotelemetring research, transmitter, radio channel, implant devices, Spine, impellent segments
Vestnik KhNU 712 Pages. 33-36

In the given job the review and the analysis of existing telemetering methods of research and diagnostics of various diseases in medicine is resulted. It is offered to use means of radiotelemetering research for registration of mechanical parameters arising on contact and lateral surfaces of impellent segments of a backbone. The block diagram of multichannel telemetering system is resulted and the basic requirements shown to this system are described



5.  Longitudinal slot radiators cut in circular waveguide
E.Y. Belogurov, V.A. Katrich, V.A. Lyaschenko
circular waveguide, axial slot, electromagnetic waves, radiation, Slot antennas
Vestnik KhNU 712 Pages. 37-41

Using method of magnetomotive forces investigations of behaviors of longitudinal slots that were cut in wall of the circular waveguide were carried out. Expressions of internal self-admittance and transfer conductance were de- rived. The possibility of creation of a tapered illumination that forms radiation pattern with low side lobes on long slot cut in circular waveguide was shown



6.  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 712 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



7.  Features of forming patterns of planar antennas arrays
A.A. Bulgakova, N.N. Gorobets, V.A. Katrich, V.A. Lyashenko
planar arrays, pattern, Sidelobes, radiator elements, interference maximums triangular grid
Vestnik KhNU 712 Pages. 71-75

Computer analysis results of an influence of a radiating aperture form of the planar array on its pattern have been presented. It is shown that there is dependence of levels of interference lobes and also near and far sidelobes of pattern in one of main positions of observation planes on number and radiators in plane which is orthogonal to main observation plane



8.  On the directive gain of the self-focusing antenna
Ya.S. Shifrin
directive gain, Self-focusing antenna, inhomogeneities, Structure function
Vestnik KhNU 756 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



9.  Radioacoustic wind sounding of the atmosphere bo un dat y layer: history of the development and perspectives
Y. N. Ulyanov, V. I. Vetrov, N. G. Maksimova
radioacoustic, wind, Sounding, atmosphere, boundary layer, profile, adaptation
Vestnik KhNU 756 Pages. 27-32

The article is devoted to the potentialities of the method of radioacoustic sounding when monitoring the vertical structure of the wind in the atmosphere boundary layer (ABL). A review of methods for radioacoustic measurements of the horizontal wind velocity and direction is based on the developments of the authors and their experience in this field as well as on the world experience. It is emphasized that the radioacoustic method for sounding the wind in ABL is perspective, since for the RAS equipment, there are not characteristic neither high levels of the electromagnetic pollution of the environment like for radiolocation wind profilers - radars nor loss of the serviceability at ligh levels of the ambient acoustic noise like for acoustic wind profilers - sodars.



10.  ELECTROMAGNETIC WAVE SCATTERING FROM ANISOTROPIC INCLUSION IN RECTANGULAR SHORT-CIRCUIT WAVEGUIDE
N.P. Zhuck, V.I. Fesenko, S.N. Shulga, O.V. Bagatskaya, He Shi
Scattering matrix, rectangular waveguide, anisotropic medium
Vestnik KhNU 756 Pages. 33-37

The problem of determination of the scattering matrix coefficients from anisotropic inclusion in one side short-circuit waveguide was considered. Calculation of the scattering matrix coefficient |S10| for the anisotropic slab in the end of the empty rectangular waveguide is presented



11.  ELECTRODYNAMIC MODELING OF COMPOSITE MEDIA WITH SIMALTENEOUSLY NEGATIVE REAL PARTS OF PERMITTIVITY AND PERMEABILITY
S.N. Shulga, I.E. Khodasevych
composite media, thin-wire resonance inclusions, permittivity, permeability, Scattering of electromagnetic waves
Vestnik KhNU 756 Pages. 38-41

This paper presents physical and mathematical model and investigation of electromagnetic properties of composite material made of straight and curved conducting resonance inclusions placed into isotropic media and forming periodic lattice. The effective constitutive parameters of the composite material are found. It is revealed that on resonance frequency real parts of permittivity and permeability of such media can assume simultaneously negative values. The problem of reflection and transmission of plane electromagnetic wave through a sequence of layers made of such composite material is solved, numerical results are presented



12.  The analytical method for a periodical sequence of the alternate grates of dielectric bars investigate
V.B. Kazanskiy
thick grate of dielectric bars, anisotropic layer, periodic structure, propagation constant, Scattering coefficients
Vestnik KhNU 756 Pages. 79-82

The electromagnetic properties of a finite periodic sequence of the thick grates of dielectric bars are investigated. The grates are identified with the homogeneous anisotropic layer of an appropriate thickness, in order to generalize, the layers which anisotropic properties of both permittivity and permeability are employed. The sequence scattering .coefficients are determined in analytical form using the circuit theory and the matrix functions techniques. Physical analysis of the frequency, angle and interference dependencies of the scattered field amplitude is carried out.



13.  Electrons in superlattice with continuous conduction band edge
M.V. Klymenko, S.I. Petrov
Superlattice, effective mass, Bragg effect, carriers confinement
Vestnik KhNU 756 Pages. 91-96

In this paper, the energy spectrum of electrons is investigated for the superlattice with continuous conduction band edge. The comparison with conventional superlattice has been realized. It is shown that in the investigated structure the energy spectrum has band structure which is caused by periodic position-dependent effective-mass. Moreover, position-dependent effective-mass leads to additional effective potential. The Bragg reflection for electrons in ballistic limit can be observed in the superlattice with continuous conduction band edge. It can be used for effective Bragg confinement of carriers. For the first time the investigations have been carried out for the case when the superlattice without band offsets has finite number of periods. The obtained results shed light on new applications of the investigated structures for THz frequency range



14.  SPECKLE INTERFEROMETRICIAN METHOD FOR ANEMOMETRICIAN OF TURBULENT STREAMS
G.N. Dolya, .N. Katunin, .V. Sadovy, S.I. Shmatkov
, Speckle interferometrician, anemometrician, Speckle painting, light-reflecting coverage
Vestnik KhNU 756 Pages. 118-122

In this paper is researched the possibility of the use of the modified speckle interferometrician method for anemometrician of turbulent streams. It is developed laser anemometer on the basis of the modified speckle interferometrician method at the applications of light-reflecting coverage. Is dependence of increase of border frequency of signals spectrum at growth of speed of stream transversal to the ray. Dependence of spectrum of fluctuations the adopted signal on the degree of the brought distortions in at a different temperature of turbulent stream is explored



15.  Arbitrary falling of wave on grate with by nisotropic layer
A.I.Adonina, R.R.Naumov, A.I.Sljusarev
grate, magnetodielectric, Stream of power, method of Riman-Gilbert, anisotropic, resonator
Vestnik KhNU 806 Pages. 22-28

A decision set the problem is conducted for and pour, proper two subsystems into which the system of equalizations of Maxwell is divided for anisotropic environments. The mixed field (in the case of the arbitrary falling of wave) is determined as a sum of two types pour. Integral descriptions are from the decision of the reduced endless systems of linear algebraic equalizations, got the method of task of Riman-Gilbert. The analysis of the graphs, partly resulted in work, allows to set influencing of parameters of structure and angles of incidence of wave on an anomaly in the dissipated field for every concrete case, and also to suppose and to confirm physical reasons of existence of anomalies a numeral account, as resonances of own waves in the opened resonator which is design the explored structure.


Download >>


16.  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 806 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.


Download >>


17.  CALCULATION AND MEASURING OF IMPEDANCE OF IMPATT-DIODE IN MILLIMETR WAVE
A.V. Arkhipov, V.T. Plaksiy, I.K. Kuzmichev, E.D. Prokhorov, A.V. Dydchenko, D.P. Chuechkov
millimeter wave range, impedance, IMPATT diode, conductance, Susceptance
Vestnik KhNU 806 Pages. 59-64

The calculated and experimental results of the impedance of the impact avalanche transit-time (IMPATT) diode for the 8 millimeter wavelength range have been presented. The dependences of the IMPATT diode impedance as a function of the normalized amplitude the fundamental current harmonic of the p-n junction and frequency have been calculated and measured. The apparatus and measuring method of the conductance and susceptance of the IMPATT diode has been developed


Download >>


18.  Selection of the high-order modes in the waveguide resonator by means a phase-shifting mirror
A.V. Volodenko, O.V. Gurin, A.V. Degtyarev, V.A. Maslov, V.A. Svich, A.N. Topkov
waveguide quasioptical resonator, excitation of the high-order transverse modes, a phase filter, Fourier optics, Selection
Vestnik KhNU 806 Pages. 87-91

The method of the space Fourier-filtration for selective excitation of separated high-order modes in the metal waveguide quasioptical resonator with a high discrimination degree of undesirable modes is realized. It is carried out numerical study of characteristics of some the lowest on loss transverse modes for the metal resonators of the submillimeter laser from resonator geometric sizes and parameters of the phase filter on the nonuniform mirror. Configurations of the phase-shifting mirrors for shaping of the high-order transverse modes in the laser resonators containing waveguides and open parts are proposed


Download >>


19.  QUEST AND CREATION OF NOVEL ACTIVE MEDIA FOR DYE LASERS IN IRE NAS OF UKRAINE
V.V. Maslov
laser dye, molecular structure, Spectrum, fluorescence, quantum yield, lasing efficiency, photostability
Vestnik KhNU 806 Pages. 92-98

Numerous studies of novel active media for dye lasers fulfilled in IRE NAS of Ukraine are generalized in present review. Peculiarities of spectral, fluorescence and lasing characteristics of some laser dye classes for visible region of the spectrum have been analysed. A special attention is focused upon effects of structure of the dye molecule and its solvent environment on these characteristics. The outlook of development for dye-doped active media has been discussed


Download >>


20.  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 834 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


Download >>


21.  The exitation Hp0 -waveguide wave of the Tbrunching with matching resonator
V. N. Mizernik, A. A. Shmat'ko
a branching of the waveguides, matching nouniformity, connection area, System of the linear algebraic equations
Vestnik KhNU 834 Pages. 8-12

In strong electrodynamics statement the problem of excitation Hp0 waveguide a wave by of the T-branching with two types matching resonator is solved: other-world and through passage. Results of calculation of amplitude-frequency characteristics of the module of factor of reflection for various parities between length of a wave and the geometrical sizes of structure are presented. Areas of value of parameters of the full coordination of wave guides are certain


Download >>


22.  Subterahertz diffraction radiation on the BWO frequency harmonics in the parametrical two-regimes electron device
E.N.Odarenko, A.A.Shmatko, P.V. Yudintcev
diffraction radiation, Smith-Purcell effect, Subterahertz waves, beam-wave interaction, nonlinear processes
Vestnik KhNU 834 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


Download >>


23.  Radiolocation complex for extra-atmospheric researches
A.F. Sorokin, A.A. Sorokin, N.N. Gorobets, O.V. Sokolova
radar, a, microwaves, Space garbage
Vestnik KhNU 834 Pages. 25-30

The creation pulse radar is offered on the basis of radio engineering systems of the National centre of management and test of space means of Ukraine for the forecast asteroid of danger, cataloguing of space garbage, research of a solar crown, near a sun and interplanetary plasma, and also for radioastronomical researches of distant space. Is shown, that at use of large-sized aerials to a ADU - 1000 and P-400 such radar at length of a wave ~ 30 cm at heights ~ 105 finds out objects with the minimal sizes ~ 0,7 cm. On a disk of the Sun the spatial sanction ~ 103 kms


Download >>


24.  Target size and shape identification by multifrequency radar measurements E. V. Ryeznik, O. I.
Sukharevskiy, A. G. Tyzhnenko
iceberg, Shape and size identification
Vestnik KhNU 834 Pages. 31-36

A new method identification of targets shape and size is proposed. In this method, the values of RCS measured on the set of discrete frequencies are compared with the theoretical ones on the same set for canonical group of target configurations (patterns). 2D patterns implementation is considered instead of 3D patterns for the sake of scattering problems simplification. To this end, 2D RCS were transformed to 3D RCS under definite conditions. The method is implemented to the iceberg identification problem in model approach


Download >>


25.  Cathode static domen in transfer electron devise
. V. Botsula, D.V. Pavlenko, E.D. Prokhorov
Static domen, velocity field characteristic, electric field strange
Vestnik KhNU 834 Pages. 104-107

The diode in which static cathode domen and under certain conditions impact ionization takes place has being considered. Transit time effect and noise oscillations takes place under impact ionization. The volatge to be lead to electric field strange abow 200 /sm (for gomogenues velosity field characteristic in ower dides) have been derermened


Download >>


26.  Potentially unbreacable ciphering on a hybrid physical-mathematical level
A. G. Tyzhnenko, E. V. Ryeznik
bit, Stochastic signals, Safe communication, hard drive protection
Vestnik KhNU 834 Pages. 108-113

A new kind of ciphering based on stochastic representation of bits as series of samples is addressed. Stochastic comparison is used for bit identification. Security level is increased by adding noise samples to signal samples and mixing signal samples with noise samples within one signal packet. The signal packet length and distribution features of signal samples among noise samples in signal packets are unique for given communication line, as well as stochastic representation of bits (0s and 1s). Using of noise in signal packets leads to enormous large computation in decrypting process which is unrealistically to do regardless what computer system is used. More to the point, the unique features of communication line mentioned above can be changed for each message that prevents information leakage in the case of stealing these ones in any previous period. Impossibility of decrypting by any reasonable time period of any message eavesdropped by a cryptanalyst guarantees the confidence of information which has permanent importance


Download >>


27.  Potential of a spherical segment which is placed within a spherical layer with circular aperture.
V.A. Rezunenko
electrostatics, Spherical segment, layer, Fredholm integral equation
Vestnik KhNU 834 Pages. 120-126

The rigorous solution of an axially symmetrical electrostatics problem is obtained. The potential of an ideal spherical segment, which is placed within a spherical layer with circular aperture, is analyzed. We use the methods of regularization, separation and inversion of summarized equations, the method of residues in singular points of analytical functions, the methods of contour integrals and integral transformations. Fredholm integral equation of the second kind with a compact operator in Hilbert space L2 is obtained. The comparison with known results and limit variants is given. The effectiveness of the constructed algorithm is confirmed. Some generalizations of the problems are considered


Download >>


28.  Capacitance-voltage measurements in selectively doped ALGAAS/GAAS heterostructures
N.B.Gorev, I.F. Kodzhespirova, E.N. Privalov
gallium arsenide, Selectively doped heterostructures, Schottky barrier, barrier capacitance, capacitancevoltage measurements
Vestnik KhNU 853 Pages. 3-7

The dependence of the measured apparent capacitance of selectively doped AlGaAs/GaAs heterostructures on the amplitude of the measuring ac voltage is calculated numerically. An expression that gives the measured apparent capacitance as a function of the true capacitance and the above amplitude is derived. Using this expression and the results of the above numerical calculation, it is shown that capacitancevoltage characteristics of selectively doped AlGaAs/GaAs heterostructures, which feature steeply dropping regions, may be measured at moderately small amplitudes of the measuring ac voltage (of the order of 100 mV) at the expense of taking measurements at two different amplitudes


Download >>


29.  Global Sensitivity analysis of the dipole matrix element according to variation of parameters of the indium surface segregation in ingan/gan quantum well
M.V. Klymenko
indium surface segregation, Semiconductor nitrides, piezoelectric polarization, dipole matrix element, global sensitivity analysis
Vestnik KhNU 853 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


Download >>


30.  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 853 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


Download >>


31.  Arbitrary falling of wave on grate with by a screen and layer of environment
A.I.Adonina, R.R. Naumov, A.I.Sljusarev
grate, magnetodielectric, Stream of power, method of Riman-Gilbert, resonator
Vestnik KhNU 853 Pages. 45-50

A decision of the set problem is conducted in the exact raising without imposition of limits on the parameters of structure, angles of incidence of wave, wave-length, parameters of environment. The variant of method of Riman-Gilbert was used for the case of the arbitrary falling of wave. A vectorial task is presented as a sum of two scalar tasks, proper subsystems into which the system of equalizations of Maxwell is divided for - and -fields. A numeral account, resulted in work as the graphs, confirms assumption about physical reasons of existence of anomalies, as resonances between active spectral accordions and own waves of the opened resonator which designs the explored structure


Download >>


32.  Diffraction of the plane acoustic wave on the hard spherical segment, shielding of the ball
Rezunenko V.A.
acoustics, Spherical segment, Shielding ball, resonance frequencies, algebraic equations of the second kind
Vestnik KhNU 853 Pages. 57-63

A solution of the axisymmetrical problem of acoustics in strict formulation is built. The acoustic potential of the velocity of the plane wave, diffracted on the hard spherical circular segment, shielding of the ball is analyzed. The method of regularization of the paired summarized equations is used. The method of the integral transformations is applied. The principal part of the summarized equations is isolated and inverted. The effectively solvable system of the linear algebraic equations of the second kind with the compact operator in the Hilbert space l2 is obtained. Comparison with the known results and limited cases of the problem is given. The effectiveness of the constructed algorithm is confirmed. Some resonance frequencies and generalization of the task are examined


Download >>


33.  Paramagnetic properties of ASO2" free radical in irradiated KDP single crystals
A.N. Levchenko
KDP single crystal, ionizing irradiation, free radicals, EPR, Spin Hamiltonian
Vestnik KhNU 853 Pages. 84-87

The electron paramagnetic resonance (EPR) spectra of AsO22- free radical in potassium dihydrogen phosphate (KDP) single crystals irradiated with gamma rays and electrons have been investigated. The angular dependences of the spectra have been measured. The number of magnetically inequivalent sites for the AsO22- in the crystal lattice of KDP has been determined. The principal values of g-factor and hyperfine structure tensor have been calculated. It is found that the radical exhibits orthorhombic symmetry. The lagest component of hyperfine tensor is in the ab crystal plane. The molecular planes of the free radicals and the ab crystal plane are mutually perpenducular. The superhyperfine structure of the spectra indicates an existence of two protons near the paramagnetic center


Download >>


34.  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 853 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


Download >>


35.  Random inhomogeneous liquid medium as a continuous laser of low-intensity modulator for excitating sound in the medium
B. G. Yemets
laser, random inhomogeneous liquid medium, interference, temperature field, optical acoustical phenomenon, Sound, excitation, modulation
Vestnik KhNU 853 Pages. 95-100

When a medium is irradiated by laser pulses, sound waves are excited in this medium, i.e., the well-known optical acoustical phenomenon occurs. To excite sound oscillations, the specific laser beam modulator is shown to be unnecessary. The role of the modulator can play the liquid itself, which is a random inhomogeneous medium. The real liquid contains suspended solids and gas bubbles of small dimensions (dust particles and the like) that move irregularly in space (fluctuations). As a result, the electromagnetic wave interference taking place in the liquid undergoes random changes. Consequently, the temperature field changes, and hence variations in the local pressure occurs (thermo-optical mechanism for exciting sound). The excitation of sound due to the laser irradiation of low intensity is observed in an increase in the gas bubbles dimensions in the liquid


Download >>


36.  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 883 Pages. 41-44

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 closed-form solution. Radiation of a ring with transient current in free space is considered. It was shown that there


Download >>


37.  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 883 Pages. 25-29

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


Download >>


38.  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 883 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


Download >>


39.  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 883 Pages. 67-72

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


Download >>


40.  Ballistic electronic transport in continuous-band superlattice under applied electrostatic field
S.I.Petrov, Klymenko M. V., Shulika O. V.
ballistic transport, Superlattice, effective potential
Vestnik KhNU 883 Pages. 12-19

We address in this work ballistic transport of electrons in semiconductor continuous-band superlattice under applied electrostatic field. Combined influence of the effective mass periodically varied in space and external electrostatic field on the electro


Download >>


41.  Own magnon polariton surface modes in the open passage resonator with gyromagnetic medium
Mizernik V.N., Shmat'ko A.A.
magnon polatiton oscillations, the ferrite resonator, a junction of waveguides, the through passage open resonator, wavegaide inhomogeneity, area of connection, System of the linear algebraic equations.
Vestnik KhNU 966 Pages. 31-36

The problem about owen modes of the open reentrant resonator partially filled is theoretically solved by gyrotropic ferrite medium and existence magnon polatiton surface (PS) mods with tall concentration of a field on boundary line of the ferrite resonator is established. The every possible combined regimes of existence of superficial and volumetric fashions are analysed, dependences of their resonant frequencies on material parameters of medium and geometrical sizes of the resonator and a ferrite layer are certain.


Download >>


42.  
Lizogubenko S.V., Kokodiy N.G.
Scattering pattern, diameter of the particles, Scattering, brightness of the light spot, beam intensity
Vestnik KhNU 966 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.


Download >>


43.  Optical synthesized apertures in holographic television systems
Titar V.P.
Holographic television, Synthesizing holograms, linear antennas, CCD-matrices, color holographic television systems
Vestnik KhNU 966 Pages. 56-67

The analysis of the modern state of investigations concerning the creation of holographic television has been carried out. The new methods of hologram formation on photo electronic devices are proposed. The scheme of the holographic television system realizing the method of synthesizing optical holograms is presented. The possibility of synthesizing three-dimensional holograms of volume objects on photo electron devices is shown. The method and principles of constructing colour holographic television system is proposed.


Download >>


44.  Signal scattering on the meteor trail
Kharchenko H.V.
Signal scattering, meteor trail, diffraction oscillations, electron density, plasma collective interaction, impulse response.
Vestnik KhNU 966 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.


Download >>


45.  

radioholographic image, radiohologram, three-dimensional image of object, Spatial resolution
Vestnik KhNU 966 Pages. 68-71

The known method of the in-phase adding up of harmonic vibrations with different temporal and spatial frequencies is examined. In ordinary aerial of accordion with different spatial frequencies in sending to the object folded in a phase and the diagram of orientation is formed thus (main and lateral petals). In other directions spatial accordions folded with different phases and fomiruyut lateral petals of diagram of orientation. If to create the multifrequency and multiposition coherent system such, that on separate aerial positions signals are accepted with different bearings frequencies, on the output of general aerial they can be laid down in a phase in certain moment of time like that as it takes a place with spatial frequencies in ordinary aerial. In this case spatial resolution of order of wave-length is provided thus.


Download >>


46.  

ballistic transport, Superlattice, effective potential
Vestnik KhNU 883 Pages. 12-19

We address in this work ballistic transport of electrons in semiconductor continuous-band superlattice under applied electrostatic field. Combined influence of the effective mass periodically varied in space and external electro-static field on the electron transport leads to new undiscovered phenomena. We consider transport at the center of the Brillouin zone as well as off-center-zone transport. Results obtained open possibility for control of electron transport in semiconductor superlattices.


Download >>


47.  

mode basis method, transient field, Spherical modes, ring current.
Vestnik KhNU 883 Pages. 41-44

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 closed-form 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.


Download >>


48.  

Slot, microwaves, waveguide, dielectric, admittance, Scattering parameters
Vestnik KhNU 883 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.


Download >>


49.  

Spurious resonance, a branching of the waveguides, matching uniformity, connection area, System of the linear algebraic equations.
Vestnik KhNU 883 Pages. 67-72

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 -branching 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 -branching of hollow wave guides, and tees with dielectric and ferrite resonators in the field of connection of waveguides.


Download >>


50.  

thermal nonlinearity, optical beam, total reflection, induced inhomogeneity, Self-defocusing.
Vestnik KhNU 983 Pages. 33-37

The interaction of optical beams in media characterized by a refractive index depending on temperature is examined. The optical pump beam is partially absorbed by the medium induces a region with an inhomogeneous refractive index. As a result complete reflection, refraction or diffraction of the signal beam on the induced optical inhomogeneity may be observed. Experimental results on the research of this phenomenon are presented. Waveguide propagation of light in the region formed by two narrow pump beams is realized.


Download >>


51.  

method of enveloping surfaces in medium, Synchrotron-Cherenkov radiation, radiation spectrum, hopping variations.
Vestnik KhNU 983 Pages. 38-47

The method of enveloping surfaces is generalized for the case of the system of electrons moving along an arbitrary defined trajectory in transparent isotropic medium. The basic relationships for the classical radiation theory of the system of electrons moving in transparent isotropic medium along an arbitrary defined trajectory are obtained using this method. The hopping variations in spectral distributions of the radiation power of one, two, three, and four electrons moving along a spiral in transparent isotropic medium are studies.


Download >>


52.  

plasma, Surface plasmons (plasmon resonances), Scattering cross section, eigenvalues.
Vestnik KhNU 983 Pages. 84-90

Plasmon resonances of an isolated plasma cylinder and if a pair of coupled plasma cylinders are theoretically investigated. Mechanism of the plasmonic modes coupling that can be considered as symmetric and antisymmetric combinations of isolated cylinders plasmons is investigated. Accurate analysis of the spectrum of different Plasmon resonances is presented. Significant enhancement of the field in the case of distant cylinders in comparison to isolated one is revealed (separation distance is near 10-20 radii). The calculation accuracy is estimated. Figures show the scattering cross section of plane wave on the isolated plasma cylinder and on the pair of coupled cylinders and the real part of the eigenfrequency of the plasmon modes. Near field spatial characteristics of plasmons are presented.


Download >>


53.  

gravimeter, Superconducting suspension, optical registration, thin films, Superconducting ring.
Vestnik KhNU 983 Pages. 107-113

This paper considers the problem of designing and developing optical-cryogenic devices using new physical principles, mathematical methods, and new superconducting materials. The sensor element is based on new ontrolled magnetic levitation phenomenon, high-precision optical registration of mechanical coordinates of levitating body, and the robust signal processing tools. A controlled self-bearing probe dynamics is also analyzed. We have shown how to produce reliable YBCO thin films with controllable surfaces and physical properties and how to integrate them in a ring form into the optical-cryogenic gravimeter so as to reduce its size and render it convenient for future space applications.


Download >>


54.  

antenna array, horizontal polarization, double slots, Slowing system.
Vestnik KhNU 927 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.


Download >>


55.  

Slot, waveguide, dielectric, admittance, Scattering parameters, Slot-waveguide array.
Vestnik KhNU 927 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.


Download >>


56.  

wavelet-analysis, continuous wavelet transform, dynamic energogram, Space radio physics, powerful non-stationary disturbance sources.
Vestnik KhNU 927 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.


Download >>


57.  

Wigner transform, Cohens transform class, space radio physics, signal processing, powerful non-stationary disturbance sources, volcano explosion, Solar eruption.
Vestnik KhNU 927 Pages. 89-95

Being a member of Cohens class of integral transforms, non-linear integral Wigner transform for analysis of the real signals and processes in geospace radar methods is applied. At samples of the May 18, 1980, explosion of Mount St. Hellens and the December 5, 2006, very strong X-ray solar eruption, the effectiveness of Wigner transform application to the processing of non-stationary, non-linear, fractal and ultrawideband signals and processes in problems of space radio physics, in particular, to the investigations of processes, accompanying the effects of powerful non-stationary disturbance sources was shown.


Download >>


58.  

microstrip resonant antenna, thermostabilization, temperature compensation, dielectric permeability, Substrate, resonant frequency
Vestnik KhNU 927 Pages. 65-70

The results theoretical and experimental researches of opportunities thermostabilization of resonant frequency microstrip antennas are given by use two-layer dielectric of substrates with opposite on a symbol and temperature factors, close on size, dielectric of permeability. The optimum ratio between the thickness of layers in a composite two-layer substrate are given. It is shown that the experimental oscillator with temperature compensation for temperature changes from -50 to +80 C the deviation of resonance frequency in the optimal variant is less than 0,1%


Download >>


59.  

Stratified structure, chirality, Fibonacci sequence.
Vestnik KhNU 927 Pages. 15-21

Optical properties of both symmetrical and asymmetrical modified Fibonacci structures of chiral and achiral isotropic layers are studied. The localization and polarization transformation of linearly polarized waves are considered. The effect of the phase shift compensation in the reflected field is shown in the case of an asymmetrical modified Fibonacci multilayer and on the basis of the developed software the series of computing experiments testifying to perspective of use of such structures in optical systems.


Download >>

founded: 59 result (s)
Development wip.com.ua - V.N. Karazin Kharkov National university