2004, volume 9, ¹ 1
A NUMERICAL-ANALYTICAL METHOD FOR THE CUTOFF WAVENUMBERS CALCULATION OF WAVEGUIDES WITH COMPLICATED CROSS-SECTION
Don N.G., Poyedinchuk A.Ye., Tkachenko V.I.
177-184
A new numerical-analytical method for the cutoff wavenumbers calculation of hollow regular waveguides whose cross-section contour has a continuous curvature or curvature with a singularity of the first type is presented. The method is based on the boundary integral equations of the potential theory and the special parametrization of the cross-section contour. Numerical realization features of this method are illustrated with the examples of the circular guide and rectangular one with rounded corners. With the aid of the perturbation theory, the analytical formulas for the cutoff wavenumbers of waveguides with piecewise linear boundaries and rounded corners are derived. The application range of these formulas is determined.
INTERACTION OF AN ELECTROMAGNETIC WAVE WITH AN ANISOTROPIC DIELECTRIC SUBSTRATE WHEN THE PERIODIC SHIELDS ARE PRESENT
Abdulkdyrov V.A., Gestrina G.N.
185-190
Interaction of electromagnetic wave with an anisotropic dielectric substrate when the periodic shields are present has been investigated. The fields reflected from the structure have been obtained in analytic form.
A PRINCIPLE OF EXTINCTION IN THE PROBLEMS OF SCATTERING ON DOUBLE-PERIODIC MAGNETO-DIELECTRIC STRUCTURES
Yachin V.V.
191-194
In the present paper a new method on the basis of the volumetric integro-differential equations for the solution of the problems of scattering from doubly-periodic magnetodielectric structures is considered. A peculiar feature of such hybrid method is the possibility to use the principle of extintion as an equivalent of the boundary conditions in traditional statement.
A SCATTERING FROM THE SLOTS IN A WAVEGUIDE WITH NONPERFECT WALLS
Yatsuk L.P., Nazarenko T.G., Mistrekov K.N.
195-199
The questions of theory of a longitudinal narrow slot cut in a broad nonperfect wall of a rectangular waveguide are considered. The coefficients of transition, reflection and radiation of the slot as well as the Ohmic losses in the region of its location have been investigated.
CONSTRUCTION OF STRUCTURAL FUNCTIONS OF ELECTROMAGNETIC INTERACTION IN A SYSTEM OF MANY RESONANCE MAGNETODIELECTRIC SPHERES
Kozar A.I.
200-210
A way of construction of structural functions of electromagnetic interaction in a system of many resonance magnetodielectric spheres is considered. The expressions for tensor functions form of electromagnetic interaction of magnetical and electrical kind of a system of spheres are obtained.
CALCULATION OF THE MAGNETIC WAVE ATTENUATION IN A RECTANGULAR WAVEGUIDE WITH FRACTAL WALLS
Misyura A.A., Onufriyenko V.M.
211-215
The results of the research of a rectangular metallic waveguide with fractional walls in the frequency range 25 – 300 GHz are presented. The attenuation coefficient of magnetic waves which propagate in this structure has been determined using the fractional integro-differential calculus. The dependence of attenuation coefficient on values of scaling index which characterizes the degree of fractionation of the walls in the waveguide has been the found. An agreement between the calculation results and experimental values is shown.
COMPARISON OF ELEVATION ANGLE MEASUREMENT TECHNIQUES OVER THE SEA
Razskazovsky V.B., Pedenko Yu.A.
216-227
Experimental results of research of special elevation angle measurement technique of a low-altitude radiation source in natural conditions over the sea surface are obtained and analysed: an off-axis monopulse technique and a symmetrical patterns technique. The measurements are executed in centimeter and millimeter wave range on the path from hundreds of meters up to several kilometers at sea state 3. Comparison of their efficiency with the now widely used monopulse sum-difference amplitude technique is carried out. The results of experimental research are added with the computer simulation. Conclusions about efficiency of the tested methods in concrete conditions are made. It is shown that the off-axis technique has a number of advantages over other technique practically in all conditions of test performance
SPATIALLY-TEMPORAL CHARACTERISTICS OF ILLUMINATED SEA SURFACE SITES OBSERVED AT SMALL GRAZING ANGLES
Kirichenko V.A., Logvinov Yu.F.
228-233
The spatially-temporal characteristics of facets of illuminated sea surface are obtained by the computer simulation. The case of backscattering at small grazing angles was studied. A good agreement of simulated results with the experimental data is shown.
STATISTICS OF RADIO SIGNALS RECEIVED BY AN MF RADAR
Panasenko S.V., Chernogor L.F.
234-247
The paper is concerned with the distribution, auto-, and cross-correlation functions for the envelope of MF radar signals. The envelope histograms are shown to follow a Poisson distribution over some time intervals and a Rayleigh-Rice distribution over others. The envelope autocorrelation interval was found to be in the 0.6 – 2.2-sec range. The cross-correlation functions exhibit clear peaks and experience dependence on sample statistics. The correlation coefficients are found to be high enough for the signals scattered from two adjacent layers spaced 3 km apart. The results are basically in agreement with those obtained by other researchers and with the theory of processes acting in the height region under investigation.
THE TROPOSPHERE REFRACTION ESTIMATION BY ATTENUATION FACTOR OF RADIOWAVE OVER HORIZON PROPAGATION
Lutsenko V.I., Belov E.N., Lutsenko I.V., Homenko S.I.
248-258
A technique of the troposphere refraction properties estimation by attenuation factor of the TV signals on over-the-horizon path is proposed. The experimental results of attenuation factor and their statistical performances on over-the-horizon paths in the diffraction and long-distance tropospheric zones are presented. Using the approach proposed, these performances are recalculated in terms of equivalent gradients of the refraction factor. A comparison with the troposphere performance direct measurements using the spheres–probes was carried out. Seasonal and daily variability of the refraction gradients and attenuation was investigated. The empirical dependences of attenuation factor fluctuations variance on the effective gradient of the troposphere refraction coefficient index were derived.
EXCITATION ON SURFACE WAVES IN MAGNETOACTIVE PLASMA BY A MOVING CHARGED PARTICLE
Khankina S.I., Yakovenko V.M., Yakovenko I.V.
259-263
The Cherenkov radiation of surface waves by a particle moving along the spiral line relative to the constant magnetic field has been studied on magnetoactive medium – dielectric (vacuum) interface. Low-frequency and high-frequency ranges where the surface electrostatic and helicon waves are excited have been considered.
THE STUDY OF SOLID SOLUTIONS HG1-XCRXSE WITH CHROMIUM
COMPOSITIONS 0,01
0,1
Ivanchenko I., Karelin S., Paranchich S., Paranchich L., Popenko N., Romanyuk V.
264-270
The experimental results related to the study of kinetic coefficients and ESR spectra of the solid solutions Hg1-xCrxSe with a high chromium concentration performed in the temperature range 4.2 < T <300 K are presented. For the samples with different chromium composition we have defined the typical temperatures corresponding to the beginning of ESR-line shape distortion, namely, the anysotropy appearance and the line center shifting. It has been determined that under conditions when the paramagnetic centers concentration exceeds a certain critical value, the fine structure lines appear in the absorption spectrum. The physical model describing the distortion spectra behavior of Hg1-xCrxSe compounds as the temperature decreas is discussed.
AN EFFECT OF HEAT PROCESSES ON THE DRIFT CHARACTERISTICS OF SEMICONDUCTOR STRUCTURES
Zuev S.A., Tereshchenko V.Yu., Starostenko V.V., Shadrin A.A.
271-275
In the given work the results of calculation of drift characteristics of semi-conductor structures on the basis of GaAs and Si are presented. The results are received with regard to the processes of heating of a crystal by the current of free carriers of a charge. It has been shown that in the mode of big currents, the growth of the drifting velocity depends on the heating of a semiconductor structure.
THE DRIFT-ORBITAL RESONANCE REGIMES IN MILLIMETER WAVE MAGNETRONS
Kulagin O.P., Yeryomka V.D.
275-281
The large-orbit and small-orbit regimes of M-type oscillator in the drift-orbital resonance mode are considered. The theoretical analysis of energy oscillator characteristics is made for each regimes. The comparison between experimental and theoretical data is fulfilled. Deductions concerning electron-wave interaction mechanism in millimeter-band magnetrons are proposed.
IMPEDANCE OF CONNECTED IN SERIES DIODES WITH NEGATIVE DIFFERENCE CONDUCTIVITY
Botsula O.V., Prokhorov E.D.
282-288
The impedance of the connected in series negative difference conductivity (NDC) diodes in the wide frequency range are analyzed. It is shown that each combination of NDC diodes corresponds the frequency range where these diodes can jointly work at one frequency. The operation frequencies for combination of InGaAs/AlAs resonance tunnel diodes and LSA diode are 50-100 GHz, for combination of the resonance tunnel diodes and Gunn diodes are 25-40 GHz.
ELECTRON TRAJECTORIES IN MAGNETIC FIELD OF MPFS WITH VARYING LONGITUDINAL COMPONENT
Bulgakov A.A., Kuleshov A.N., Yefimov B.P.
289-294
The theoretical and experimental researches of electron behavior in MPFS with varying longitudinal component are given in this paper. We obtain the analytical expressions for description of electron motion in such systems. It is shown that we can effectively influence on beam focusing and beam passing to the collector by choosing the initial electron velocities.
MILLIMETER WAVE BAND MODULES
Karushkin N.F.
295-303
The results of development of semiconductor modules of the millimeter range are considered: pulse transmitting devices with using IMPAT diodes, high divisible frequency converters, managing devices on pin-diodes. The power sources using of ring diodes of the distributed type are offered.
A MODEL OF THE SIGNAL FOR THE ALGORITHM OF OBJECT IDENTIFICATION
Sytnik O.V.
304-307
The model of a periodically correlated random process for the description of the Doppler response of an identified object is offered. Probing signal of a pulse-Doppler locator working in the range of ultrasonic frequencies, being reflected from mobile objects gets the frequency modulation. By the character of this modulation it is possible to judge about the studied object and its properties. For identification of alive people behind a visual opaque barrier in the algorithms of processing a property of periodic repeatabsility of characteristics of a signal of reflected from a person’s chest is used. The model of the reflected signal is developed proceeding from the analysis of the records of the signals received under various conditions. The mathematical tool of the periodically correlated random processes is applied for its description. The use of the offered model at synthesis of optimum algorithms of identification of objects allows one not only to receive a wide class of algorithms but also to solve a problem of selection of an optimum function of losses. The features of construction of the algorithms of identification are discussed, with the availability of the reflections of a useful signal from immovable obstacles and the operator.
THE CONTACTLESS METHOD OF DETERMINATION OF THE SPATIAL POSITION OF A MAGNETOLEVITATIVE VEHICLE
Plaxin S.V., Sokolovskiy I.I.
308-311
The auto generator-sensor for small distance measurements and their deviations between the moving objects, built on the basis of two SHF-generators is investigated. One of the generators is stable, the radiation frequency of the second one is connected with the change of phase distance between the objects. The different frequency is informative. The criterion for achievement of maximum sensitivity of sensor is determined.
A FREQUENCY SHIFTER BASED ON THE CROSS DOPPLER EFFECT (A RELATIVISTICAL FREQUENCY SHIFTER)
Polupanov V.N.
312-314
The scheme of quasioptical (QO) frequency shifter (FS) using the cross Doppler effect has been offered for the first time. Such a scheme provides a continuous frequency shift just as as the polarization FSs do. The analysis of the physical processes occurring in FS has been made. It is found that, in addition to the ordinary force of pressure, on the mirror moving perpendicular to incident radiation, a transversal force coinciding with the mirror displacement direction acts. FS scheme provides four-fold reflection of a QO beam from the mirror and excludes the impact of parasitic vibrations of the mirror on the transmitted radiation phase. Application of the considered FS can be useful in homodyne measuring systems of THz and higher frequencies, up to the optical ones.