1. 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.
2. 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
3. Integral representation of green function in parallel-plate and rectangular waveguide, and in resonator as well
V.A. Katrich, F.S. Novokhatsky
Waveguides, Green function, fundamental solution, radial function, elliptical teta- function, image method, calculus of residues, integral transformation, grating, formal variative
Vestnik KhNU ¹712 Pages. 67-70
The known results connected with Green function representation by elliptical theta-function are generalized. New representations of Green function for some widely used types of waveguides are obtained. Earlier, these Green functions are presented either in form of series with nonuniform convergence or in form of integrals containing Hancel functions, which are reduced to asymptotic expressions in far zone. On this work integral representations of Green functions are obtained for Cases where the quadrature formula exists. The method of analytical continuation with parameter is applied
4. 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 ¹756 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.
5. SELECTIVE excitation of the HIGH-order MODES IN THE waveguide quasioptical RESONATOR
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, an amplitude filter, Fourier optics
Vestnik KhNU ¹756 Pages. 123-131
The method of the space Fourier-filtration for selective excitation of separated high-order transverse modes in the waveguide quasioptical resonator with a high discrimination degree of undesirable modes is proposed and realized. It is carried out numerical study of characteristics of some the lowest on loss transverse modes of the dielectric and metal resonators of the submillimeter laser from geometric sizes of reflectors and parameters of the space filter on the nonuniform mirror. Configurations of the amplitude-stepped mirrors for shaping the high-order transverse modes in the laser resonators containing waveguides and open parts are proposed
6. Directed and polarization characteristics of the aperture of the circular waveguide with impedance flange
N.N. Gorobets, V.M. Dakhov, I.V. Gorbach
microwave, antennas, Waveguides, polarization, pattern
Vestnik KhNU ¹806 Pages. 3-7
The amplitude and polarization patterns of the radiator in the form of the aperture of circular waveguide with impedance flange, excited by the dominant wave, have been measured by the method of the indicator antenna with polarization plane rotation. It is shown that such radiators have an axial-symmetric pattern, a wide polarization pattern and a low level of side lobes.
7. 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.
8. 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 ¹806 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
9. Near electromagnetic field of combined waveguide-slot radiators in matter
S.L. Berdnik, V.A. Katrich, M.V. Nesterenko, S.V. Pshenichnaya
rectangular waveguide, Waveguide-slot radiator, material medium, hyperthermia, Galerkin's method
Vestnik KhNU ¹834 Pages. 85-88
The problem about the electromagnetic waves radiation into the homogeneous isotropic medium by the system of combined waveguide-slot radiators in the broad wall of a rectangular waveguide has been solved in a rigorous self-consistent formulation. The spatial distribution of the near field intensity in the half-infinite material medium with the electrophysical parameters, corresponding to some man's tissues, has been investigated
10. 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
11. 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 ¹966 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 (ÌPS) 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.
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.
Waveguide resonator, misalignment of the mirrors, terahertz range, energy losses, mode composition, polarization
Vestnik KhNU ¹983 Pages. 18-22
The influence of the curvature of the spherical mirror for metallic waveguide resonator of submillimeter laser (lambda = 0.4326 mm) on energy losses and the mode composition of radiation is investigated. It is shown that the presence of quadratic phase aberrations in the mirrors of the waveguide cavity with an increase of its Fresnel number at monotonically decreasing of the energy losses for fundamental asymmetric mode TE11q due to a decrease of waveguide losses also leads to their substantial non-periodic oscillation.
Wave equation, exact solutions, localized waves, Bateman solution, general astigmatism.
Vestnik KhNU ¹983 Pages. 77-83
A new class of exact non-harmonic in time solutions of 3D wave equation is established. This class is a generalization of the known complexified relatively undistorted Bateman-type solution, involving an arbitrary function, waveform. Argument of this function is much similar to that which appears in general astigmatic paraxial Gaussian beam. Special choices of the waveform allow general astigmatic beam-like and packetlike waves with Gaussian-type localization in space and time.
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.
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.
Wigner transform, Cohen’s transform class, space radio physics, signal processing, powerful non-stationary disturbance sources, volcano explosion, solar eruption.
Vestnik KhNU ¹927 Pages. 89-95
Being a member of Cohen’s 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.
founded: 17 result (s)