1. 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 ¹834 Pages. 31-36
A new method identification of target’s 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
2. 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 ¹712 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
3. The accumulation of gas in galactic objects
Sorokin A.A., Sorokin A.F., Zaharova M., Sokolova O.V., Gorobets N.N.
astrophysics, galactic objects, the accumulation of gas
Vestnik KhNU ¹883 Pages. 3-7
The mechanism of the accumulation of gas in the galactic objects submerged in the large-scale magnetic field is examined. As a consequence of the diamagnetism of the plasma subsystem of object, the stopper geometry of magnetic field with the radial electr
4. The analytical method for a periodical sequence of the alternate grates of dielectric bars investigate
thick grate of dielectric bars, anisotropic layer, periodic structure, propagation constant, scattering coefficients
Vestnik KhNU ¹756 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.
5. The exitation Hp0 -waveguide wave of the T–brunching 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 ¹834 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
6. The finite difference scheme in time domain (FDTD) and analytical solution to Klein-Gordon equation
Yu Zheng, B. A. Kochetov, A.Yu Butrym
Klein-Gordon equation, FDTD, finite difference equation, Laguerre impulse
Vestnik KhNU ¹712 Pages. 91-94
A finite difference algorithm for solving inhomogeneous Kleine-Gordon equation in Time Domain with arbitrary waveform pointwise source is considered in the paper. The numerical results were compared with analytical so-lution that was obtained using Laplace transformation in a convolution operator form. The results confirm validity of both the obtained numerical algorithm and the analytical solution
7. The Gaussian beam scattering on the bounded sequence of alternate grates of dielectric bars
V.B. Kazanskiy, V.R. Tuz, D.V. Yudintsev
Gaussian beam, thick grate of dielectric bars, anisotropic layer, periodic structure
Vestnik KhNU ¹756 Pages. 83-86
The Gaussian beam scattering on bounded periodical sequence of thick grates of dielectric bars are investigated. Identification of discrete structure with appropriate thickness homogeneous anisotropic layer was carried out for define sequence basic element transmission matrix. The sequence scattering coefficients were written down via Mougin polynomials. The effects of form distortion, beam splitting into several beams, side shift of beam axe were shown. Their correlation with scattering coefficients phase and module angle dependence of separate grates was established.
8. The geometrical approaches to the calculation of propagation of Gaussian beams in hollow metal waveguides in the terahertz range
Gurin O.V., Degtyarev A.V., Maslov V.A., Svich V.A., Senyuta V.S., Topkov A.N.
metal waveguide, Gaussian beam, terahertz range, geometrooptical approach, transmission coefficient
Vestnik KhNU ¹966 Pages. 3-8
A comparison of the results of calculations of the transmision for Gaussian beams in hollow circular metal waveguide using geometrooptical procedures by Frost and Crenn with the results of experiments in the
terahertz range is performed. The conditions of applicability of these methods to study the transmission characteristics of metallic waveguides of different lengths were found. It is shown that in this range the geometrooptical approach, proposed by Frost, provides satisfactory results only for short waveguides, the length of which corresponds to the condition of the near zone. The geometrooptical approach by Crenn is applicable to both short and for long waveguides.
9. 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
10. 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.
11. THE INFLUENCE OF MUTUAL COUPLING ON RADIATION CHARACTERISTICS OF ANTENNA ARRAY FOR VIDEOPULSE EXCITATION
mutual coupling, finite TSA arrays, Van-Atta array, videopulse
Vestnik KhNU ¹756 Pages. 57-60
In paper antenna array from finite number of the elements, which are exited by a videopulse is observed. The model for calculation of radiated fields of antenna taking consideration of mutual coupling between elements is proposed. A directed characteristics analysis of the retrodirected systems, Van-Atta array, from finite number of elements and wave form of radiated and reradiated signals are investigated in case of excitation by a videopulse. Recommendations to decrease mutual coupling is proposed. The case of useful influence on characteristics of a radiated pulse signal is considered
12. 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
13. The spectrum of current oscillations of Gunn diodes with the impact ionization in moving domains
D.V. Pavlenko, E.D. Prokhorov
Gunn diode, impact ionization, UHF-noise
Vestnik KhNU ¹712 Pages. 123-126
The results of the numerical simulation of the GaAs Gunn diode with electric field strengths, enough for development of the impact ionization in the moving high-field domains, are presented. The form of current oscillations and frequency spectrums is in good agreement with experimentally measured data. It is shown that the Gunn diode, operating under conditions of the impact ionization, may be used as a source of wide spectrum UHF-noise
14. The xecl laser with the adjustable shape and duration of generation pulse
S.S. Anufrik, A.P. Volodenkov, K.F. Znosko
LC- contour, XeCl laser, excitation system, generation energy, pulse duration.
Vestnik KhNU ¹983 Pages. 3-10
The generation parameters of LC-contour excitation system are studied for electro-discharge excimer XeCl laser using a Ne–Xe–HCl mixture. A computation model is developed for finding the generation parameters. It has allowed us to calculate current, voltage and generation power oscillograms for all parameters of the electrical excitation system. The program of XeCl-laser modeling enables to calculate an electrons, atom and molecule concentrations, specific energy deposition in active medium also. By means of program Bolsig + calculation of rate coefficients of reactions with participation of electrons is executed. It is shown that generation of short radiation pulses (20 ns) and relatively long pulses (60 ns) is possible due to changing of LC- contour parameters. Energy of generation reaches a maximum at use of small values of peaking capacity, which are significantly smaller then value of storage capacity.
15. Theoretical investigation of photonic crystals by means of analysis of photonic density of states maps
photonic crystal, photonic density of states, transmittance spectrum, plane wave expansion method, finite differences method
Vestnik KhNU ¹853 Pages. 77-83
In the work, there have been computed the photonic density of states maps of the 2D photonic crystal by means of plane waves expansion method by the analogy with photonic band gap maps. The photonic density of states maps allows precise determination of the parameters of photonic crystals during the design process of the photonic crystal-based device. Moreover, there have been carried out the comparison with analogous characteristics obtained by the finite differences time domain method. Comparison results indicate the similarity of results obtained by two methods, however, the computation of photonic density of states maps requires much less time at the same computation precision. Moreover, in the work there have been carried out the comparison between the efficiencies of the photonic density of sates maps and the photonic band gap maps analysis methods
16. Theory of the millimeter waves o-type clinotron amplifier
E.N. Odarenko, A.A. Shmat'ko
nonlinear multidimensional theory, clinotron amplifier, electrons settling
Vestnik KhNU ¹806 Pages. 75-81
Nonresonant amplifier O-type system with inclined focusing field is considered. Theoretical investigation is carried out within the framework of the beam-wave interaction multidimensional model. Input signal power, focusing field magnetic induction value and electrons settling on the electrodynamical system surface are taking into account
17. 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.
18. 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.
founded: 18 result (s)