1. 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. 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
2. 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. 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
3. 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
4. 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.
5. 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
6. 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
7. AlN/AlxGa1-xN resonance tunnell diodes
D.V. Pavlenko, E.D. Prokhorov
nitrides, quantum well, NDC, oscillation efficiency.
Vestnik KhNU ¹756 Pages. 105-108
Double and threefold compounds of nitrides AIN/AIGaN resonance tunnel diodes using height of barriers are concedered. In the quantum well of diodes there are a plenty energy levels. Electron energy levels in quantum well with variable structure of interconnections AlGaN are determined. The current - voltage characteristics of resonance - tunnel diodes with number of levels in a quantum wall up to five has been calculated. The RTD can have up to five sites with negative differential conductance are demonstrated. The possible RTD oscillation efficiency on all sites of negative differential conductivity at difference barriers and quantum well's material are determined.
8. Amplitude and noise features of detectors a mm of range of lengths of waves on base of contacts a metal-semimetal BiSb
O.N. Sukhoruchko, V.T. Plaksiy, E.D. Prokhorov, A.V. Dyadchenko
contact metal-semimetal BiSb, power zones, contact a metai-semimetal BiSb, millimeter range of lengths of waves, relative noise temperature, influence of displacing and resistances of contacts on sensitivity
Vestnik KhNU ¹756 Pages. 113-117
In work are brought results of analytical and experimental thermoelectrical detector study with the point contact a metal-semi-metal BiSb. Determined relative noise temperature, as well as influence of displacing and resistances of contacts on the sensitivity in 8 mm range of waves.
9. 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. 35-40
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
10. Analysis of polarization characteristics of electromagnetic waves in non-orthogonal linearly polarized basis
Gorobets N.N., Chekalin , Chekalina G.N.
ålectromagnetic wave, electric field strength,time-distance curve, harmonic basis, the expansion of the harmonic, the polarization model
Vestnik KhNU ¹966 Pages. 50-55
We solve the problem of determining the polarization characteristics – coefficient of ellipticity and orientation angle of the polarization ellipse and the direction of rotation of the polarization vectors of linearly polarized basis with arbitrary angle between the components of the electromagnetic wave. In the special case of orthogonal linearly polarized basis obtaind solutions coincide with the known one. An algorithm for constructing a model of elliptically polarized waves had been elaborated in this article as the totality of hyperbolic and elliptic circles.
11. 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
12. 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
13. 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.
14. 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 ¹853 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 Å- and Í-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
15. Arbitrary falling of wave on grate with by ànisotropic layer
A.I.Adonina, R.R.Naumov, A.I.Sljusarev
grate, magnetodielectric, stream of power, method of Riman-Gilbert, anisotropic, resonator
Vestnik KhNU ¹806 Pages. 22-28
A decision set the problem is conducted for Å and Í 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.
16. 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
founded: 16 result (s)