2003, volume 8, ¹ 2
EFFICIENCY OF EXCITATION OF OPEN RESONANT SYSTEMS
Bulgakov B.M., Natarov M.P.
175-179
The process of excitation of open resonator by local sources has been considered on the base of simple model of the hemispherical open resonator. The influence of displacement of sours from axis of resonator and influence of magnitude of the loaded Q-factor on efficiency of excitation are investigated. It has been shown, that synchronous excitation of the resonator by several local sources increases efficiency of excitation. The synchronous excitation of resonator is energetically more favorable if it excited by several local sources. It promotes mutual synchronization in system of the oscillators located in the common resonator.
EXTENDING “THE PORT REFLECTION COEFFICIENT METHOD” FOR CALCULATION OF S-MATRICES, USING REDUCED NUMERICAL MODELS
Kirilenko A., Kulik D., Senkevich S., Tkachenko V.
180-186
New essential details of “the port reflection coefficient method”, providing reconstruction of a multiport S-matrix by the ones for the same multiport, having several shorted ports, were considered. The ways for calculation of multimode matrix and for elimination of transmission matrix sign doubts have been put forward. The main result consists in a minimization of the calculation errors by using a special choice of intermediate model geometries. The method under consideration is of particular assistance at solving the analysis and design problems of complicated multiports with coordinate boundaries by the generalized mode-matching technique.
HEMISPHERICAL CAVITY FOR THE MEASUREMENT OF DIELECTRIC PERMEABILITY IN SMALL VOLUME OF A STRONGLY ABSORBING LIQUID
Eremenko Z.E., Ganapolskii Å.Ì.
187-196
We propose the new method of microwave dielectric permeability measurement in a small volume of a strongly absorbing liquid. The method is based on the use of the hemispherical cavity resonator, which contains a small spherical cell filled with a measured liquid. The characteristic equation for oscillations of an electromagnetic field in this resonator has been received and analyzed. On this basis the working mode of oscillations and optimal sizes of a measuring cell have been found. We found the effect of electromagnetic field extrusion from a small cell filled with a liquid of the large values of the real and imaginary parts of dielectric permeability. The method has been realized experimentally in X band. The predicted theoretically effect of the field extrusion has been verified experimentally. The algorithm of complex dielectric permeability determination of liquid via the measured values of the resonator quality factor and frequency displacement have been found.
ELIMINATION OF A SINGULARITY IN THE PROBLEMS OF SCATTERING ON THREE-DIMENSIONAL MAGNETO–DIELECTRIC STRUCTURES WITH THE CHOSEN DIRECTION
Yachin V.V.
197-200
In the present paper the integro-differential equations are considered in the source region. Integrated volume is partitioned into two parts. One of the parts is associated with the Green function in the area outside of a source region, another is completely determined by geometry of volume chosen for elimination of a singularity of the Green function. The given value is determined mathematically, so supposes also physical interpretation: it can be considered as a tensor of depolarization. The explicit expression for a tensor of a depolarization can be found for the series of physically infinitesimal volumes of the elementary shape, which are commonly used in numerical integration or finite-difference solution schemes. In the paper the tensor of a depolarization associated with a unit cell of a parallelepiped form is obtained. The simple procedure, suggested in the paper, allows to improve convergence and accuracy of the method of volume integro-differential equations.
PROPERTIES OF REFLECTING GRATING CONSISTING OF SHORTED RECTANGULAR WAVEGUIDES IN AUTOCOLLIMATION REGIME
Ggibovskiy A.V.
201-205
The ability of realization on the effect of total non-mirror reflection of plane TE and TM waves diffracted from the model of reflecting two-periodical grating of rectangular shorted waveguides has been shown. Modules of amplitudes of spatial harmonics via the length of shorted waveguides have been calculated in autocollimation regime. The results obtained can be used for instance in constructing of open resonators when one mirror is two-dimensional grating of shorted waveguides.
THE FIGURED NUMBERS (ARITHMETICAL PROGRESSION) AND ELECTROMAGNETIC WAVES SCATTERING ON SPATIAL LATTICES OF THE RESONANT MAGNETODIELECTRIC SPHERES
Kozar À.I.
206-212
Solution of the problem of electromagnetic waves scattering on special composite spatial lattices of resonant sphere was considered, their spatial distribution is subordinate to figured numbers. The expressions for the scattered waves are derived.
SELECTIVITY CHARACTERISTICS OF THE FIRST AND SECOND BRAGG DIFFRACTION COMPONENTS DURING LIGHT INTERACTION WITH CROSS SECTIONAL ULTRASONIC WAVE IN SINGLE-AXIS CRYSTALS
Cherkashina E.L.
213-217
Analytical expression that enables to conduct comparative analysis of selectivity characteristics of the first and second Bragg diffraction components during light interaction with cross sectional ultrasonic wave in single-axis crystals are introduced. The differences in the characteristics of spatial components were described and optoacoustic interaction parameters defined based on the required selectivity values and spatial components diffraction efficiency. It was shown that it is the selectivity of the first and second order diffraction that mostly depends on the optical wave polarization, than the selectivity of the first order components.
WAVEGUIDE BEND MATCHED BY THE STEPPED MITER
Kulishenko S.F., Kirilenko A.A., Senkevich S.L.
218-220
The 2D problem of the stepped mitered waveguide bend is considered for both E and H polarizations of incident waves. The method used here for analysis is the mode-matched technique. Geometric parameters of such a device that can provide the low level of the return loss within the whole operating frequency band are found for WR90.
ANISOTROPIC EFFECT OF A ROUGH SEA ON ANGULAR DEPENDENCES OF THE OCEAN MICROWAVE RADIATION
Komyak V.A., Shilo S.A.
221-228
Experimental results of the azimuth anisotropy measurements for the rough sea-surface radio brightness are under discussion here. A statistically valid model of the sea surface has been proposed as a set of dual-slope prisms, orthogonal oriented to the surface wind direction. The conformity of results with other models and the adequacy of dependencies for wind contribution to the brightness temperature been estimated on the basis of this model and experimentally obtained, have been noted in the work. Sea wind-roughness peculiarities responsible for the behavior of angular dependencies of the azimuth anisotropy of radio brightness contrasts are interpreted here.
ON CONVOLUTION TYPE EQUATION OF INVERSE REFRACTION PROBLEM
G.A. Alexeev, M.V. Belobrova
229-231
The inverse refraction problem within framework in the geometric optical approximation made impossible the reconstruction of the refraction index profile of the Earth’s atmosphere on the surface measurements of the wave refraction angle of the radiosource, which is on the moving satellite. In the work the analysis of the probabilities of the numerical solution of the inverse refraction problem, which it is reduced to an integral Fredholm equation of the first sort of convolution type has been made. It is shown, that the methodical error of the equation solution by an integral Fourier transform method, which is predetermined by a hipping of the time dependence of the refraction angle outside of the measurement interval by the different ways (in particular, zero values), in the real situations exceeds the errors, caused by the regularization and approximated measurement of the refraction angle.
ACCURACY AND SENSITIVITY OF HTS FILMS SURFACE RESISTANCE MEASUREMENTS USING QUASIOPTICAL DIELECTRIC RESONATORS
Barannik A.A., Bunyaev S.A., Cherpak N.T.
232-236
The most probable error (MPE) analysis of the high-Tc superconducting (HTS) film surface resistance Rs measurement using quasioptical dielectric resonator (QDR) has been carried out depending on the resonator basic performance and dielectric properties. It is shown that using the QDR made of single crystal leukosapphire one can achieve the extremely low meanings of the measurement error and the most high sensitivity of the Rs measurement at low temperatures. Numerical evaluations are presented for 8-mm wavelength range. In partially, minimal measurable value Rsmin < 1 μΩ at T < 4.2 K is obtained based on the sapphire single crystal properties and performance of the modern microwave network-analyzers.
SURFACE ELECTROMAGNETIC OSCILLATIONS IN A SEMI-CONDUCTING SPHERE
Litvinenko V.S., Prokopenko Yu.V., Filipov Yu.F.
237-240
Spectral characteristics of a semi-conducting sphere were studied for the first time. It is shown that except volume high-frequency oscillations the sphere resonator has a surface oscillation. Inside a sphere the amplitude last is exponentially decreased along radius under resonator surface. For large values of polar index, the surface oscillation is come in a surface plasmon existing on a semi-conductor plane boundary.
SPECTRUM OF NONLINEAR SURFACE POLARITONS IN SEMIMAGNETIC SEMICONDUCTORS IN THE EXTERNAL STATIC MAGNETIC FIELD
Beletskii N.N., Borisenko S.A.
241-246
In the articles the influence of the external static magnetic field on the spectrum of the nonlinear surface polaritons in semimagnetic semiconductors being in a phase of antiferromagnetic ordering is investigated. It is shown that in the external static magnetic field the nonlinear surface polaritons possess the property of the nonreciprocal propagation. The influence of the electron plasma frequency on the dispersion properties of the nonlinear surface polaritons with monotonic and non-monotonic decaying of the electric field from the semimagnetic semiconductor boundary is determined.
DIFRACTION RADIATION OSCILLATORS WITH THE OPEN RESONATOR PARTLY OFF THE VACUUM PUMPING AREA
Skrynnik B.K., Korneenkov V.K., Senkevich Ye.B.
247-253
The open resonator of a packetized diffraction radiation oscillator is considered to have a linear (2-mirror) or ring-shaped (3-mirror) configuration, with being such that its (resonator) volume is partly off the vacuum pumping area. In the case of fundamental mode excitation (TEM00q), electron beam in the 2-mirror semi-symmetrical OR interacts with the standing wave whose front is parallel to the plane mirror surface; the diffraction radiation therewith keeps the OR axis difraction. In the ring-shaped OR, the electron beam interacts with the travelling wave which follows a closed path along the 3-mirrior OR axes, i.e. at the spectacular angles to the mirror surface; the diffraction radiation is directed at one of the spectacular angles along the OR axes depending on the electron velocity. In the case of high-order excitation (e.g. TEM01q), the oblique wave incidence on the grating in the semi-symmetrical producers a pair of “synchronous” harmonic, resulting in the diffraction radiation oriented at one or the other spectacular angles to the resonator mirror axes depending on the electron velocity.
ON THE SELECTION OF THE TYPE OF A STARTING CATHODE FOR A PULSE MAGNETRON WITH THE COOL SECONDARY-EMISSION CATHODE
Suvorov A.N., Naumenko V.D., Myand V.A.
254-258
The work presents the results of the research on the durability of various dispenser cathodes for the purpose of selecting the type of a starting cathode for the 3-mm range magnetron using the secondary emission from the main platinum cathode. There have been studied the cathodes with standard impregnation, the cathodes with the additions of oxides of silicon and scandium to the standard impregnation and also the cathodes with an osmium film applied over the emissive surface. The results of the tests have shown that, in a store of active substance, all four types of cathodes are capable of ensuring the required durability of 5000 hours. However, in durability and property reproducibility, the cathodes with an osmium film, which have been chosen as starting ones for use in durable magnetrons, have markedly stood out. The tests carried out with such magnetrons have proven the correctness of this choice, in so far as the operating time have exceeded 5000 hours for each of three devices, which far exceeds the previous results for this range.
THE CONFORMAL MAPPING MATHOD FOR ANALYSIS OF HIGH FREQUENCY ELECTRO-MAGNETIC FIELDS OF SLOW-WAVE STRUCTURES. CH. II. ELECTRODYNAMIC SOLUTIONS EQUIVALENT TO ELECTROSTATIC SOLUTIONS
M.V. Mil`cho
259-268
It is the second part of the paper cycle, which contained three parts. The auxiliary exact electrodynamic solution is obtained for the unclosed comb. This solution is the result of the incidence of some set of waves on the comb surface both from the free space and comb slot wave-guides. The electrical field of this solution is expressed with a high accuracy in terms of the quasi-static solution, which was obtained in the first part of the paper. “Higher” auxiliary solution, which correspond to the case of identical potentials on unclosed comb sheets are considered. The solution of concrete slow-wave systems are express in the form of the linear combination of the all these unclosed comb solutions.
ANALYSIS OF THE ELECTRON-OPTICAL SYSTEM OF THE DIFFRACTION RADIATION OSCILLATOR WITH RECUPERATION OF THE “WORKED’’ ELECTRON BEAM ENERGY
Korneenkov V.K., Lopatin I.V., Miroshnichenko V.S., Tishchenko A.S.
269-274
The features of the increasing of the technical efficiency for the diffraction radiation oscillator (DRO) with recuperation of the “worked” electron beam energy are considered. The trajectory analysis of the electron beam movement for DRO with single-stage collector was carried out, and the critical decreasing of the collector voltage for non-disturbed stability operation of the DRO was found. The increasing of the overall efficiency from 11,5% to 25% was obtained in the experimental model of the DRO, having single-stage collector and 100 watt of the output power.
ON THE EXCITATION MODES OF MAGNETRON-TYPE GENERATORS
G.A. Alexeev
275-278
The analysis of the excitation mode of an M-type generator with the injected electron beam is made idepending on the magnetic field value with regard to the change of the kinetic and potential electron energy.It is shown that the physical mechanism which predetermines the excitation mode in the M-type generators is the change of the average (drift) electron velocity in the interaction space. But it becomes apparent only when the transversal magnetic field is weak enough. The increase of the magnetic field from «weak» to infinite gives rise to the change of the excitation mode from soft to hard.
ABOUT WORK OF TED’S WITH TWO INP0.7AS0.3-IN0.4GA0.6AS ACTIVE REGIONS
Arkusha Yu.V., Prokhorov E.D., Storozhenko I.P.
279-286
Work of TED’s with consistently connected InP0.7As0.3 and In0.4Ga0.6As active regions have been studied by means of two-temperature model of transfer electron effect in the semiconductor. The energy and frequency characteristics of the TED with various type of metallically cathode contact (height of the band 0.04 eV) have been found. The energy and frequency characteristics of the TED with two active regions and blocking metallically cathode contact have been found to be growing out complex interaction of the physical processes occurring simultaneously in two regions. Such TED’s have the highest output power flow about 40 kW/ñì2 at frequency ~42 GHz and at efficiency ~20%. The TED’s with antiblocking metallically cathode contact works, as the diode with heterocathode, that is in generation of current oscillation participates only In0.4Ga0.6As active region.
MODELING OF TED’S ON A BASIS OF VARIBAND SEMICONDUCTORS
Storozhenko I.P.
287-294
The two-temperature model transfer electron effect in the variband semiconductor is received. TED’s on a basis of variband Inx(z)Ga1-x(z)As with the help of this model have been studied. Semiconductor composition compound x(z) in active region of TED’s linearly is carried out depends on coordinate. Is shown, that the work of the TED with by variband active region is defined by dependence on coordinate of frequency electron concentration relaxation in a Ã-valley of Inx(z)Ga1-x(z)As. Dipole domains are transited in the TED if the specified frequency decreasing function of coordinate (in Inx(z)Ga1-x(z)As it occurs, if x(z) grows). Accumulation layers are transited in the TED if the specified frequency not decreasing function of coordinate. The GaAs-In0.4Ga0.6As TED have the highest output power flow about 6.5 kW/ñì2 at frequency ~37 GHz and at efficiency ~12%.
STATISTICS OF INTERFERENCE SUPERIMPOSED ON MF RADAR SIGNALS
Panasenko S.V., Chernogor L.F.
295-303
The paper is concerned with the distribution, auto-, and cross-correlation functions of the interference envelope squared in the radio channel. The basic types of interference, the approximate values of their power, and the relative contribution to measurements taken with the MF radar are presented. The distribution of the envelope is shown to obey the Poisson law, which may be due to interference from a small (not more than from 20) number of radio stations emitting pulses. The correlation interval of the squared interference, inferred from the experimental data, is determined by the rate of sampling the signal at the antenna output, which indicates that the interference is wideband. The absence of a noticeable spatial and inter-polarization correlation indicates that the antennas receive interference signals from various directions via the side lobes of the antenna pattern.
A METHOD OF IDENTIFICATION OF RANDOM SOURCES
S.A. Krivenko
304-309
The paper describes a method of identification which can be realized with the help of microprocessors. The new method makes it possible to improve the identification accuracy and does not require long-term training for every new random source.