2006, volume 11, ¹ 1
AXIALLY NO SYMMETRIC EIGEN MODES IN OPEN RESONATOR WITH SPHERICAL MIRRORS
Svishchov Yu. V.
7-18
Mathematically strong model for axial-no symmetric eigen modes of electrical type of open resonator with spherical mirrors is constructed. Under supposition of the spectrum existence, it is proved that the spectrum is discrete, of finite multiplicity, and with the only accumulation point on infinity. Theoretical analysis of spectral characteristics of the open resonator has been done for the case, when wavelength is comparable with the resonator dimensions. The scope of correctness of a few well-known asymptotic models of the resonator has been found.
PROBE DESIGN FOR NEAR-FIELD MEASUREMENTS IN THE MILLIMETER WAVELENGTH RANGE
Brovenko I. Ya., Ivanchenko I. V., Popenko N. O., Chernobrovkin R. E.
19-23
The new probe design for measurements of amplitude and phase near field distributions in millimeter wavelength range is presented. The aforementioned probe as the rectangular waveguide, particularly filled with a dielectric, has developed on the basis of numerical simulations and experimental investigations. The probe’s capability is illustrated by the model experiment with the artificial dielectric.
RADIATION PROPERTIES OF A TWO-ELEMENT PHASED ANTENNA ARRAY CONSISTING OF RECTANGULAR WAVEGUIDE SECTIONS EXCITED BY A SURFACE WAVE
Gribovsky A. V.
29-31
The operator method has been applied to investigate radiation properties of a phased antenna array whose elemental cell consists of two rectangular waveguides with mutually orthogonal walls. It is shown that the scanning sector of the main lobe is increased significantly as compared with the phased antenna array composed of elemental cells with parallel orientation of the waveguide. The radiation intensity within the scanning sector remains practically unchanged. Polarization characteristics are calculated. The results show that the phased antenna array with mutually perpendicular waveguiding channels is capable of radiating both left-hand and right-hand polarized electromagnetic waves.
RADIALLY THREE-LAYERED DIELECTRIC RESONATOR WITH PERFECT CONDUCTIVE END WALLS
Prokopenko Yu. V., Filippov Yu. F., Shipilova I. A.
32-37
The equation for complex frequencies of a radially three-layered dielectric cylindrical resonator with perfect conductive end walls was obtained. The studying of influence of a middle layer, filled different substances, on a frequency and quality factor of resonator was carried out. Spectral and energy characteristics of a resonator with a whispering gallery oscillation were studied at different thickness of middle layer and its position along the radius. Different nature of behavior of an eigen frequency of resonator was obtained filling a middle layer by liquid with both small and large losses.
INFLUENCE OF THE UPPER LAYER OF SOIL ON THE CM AND MM RADIO WAVES BACKSCATTERING
Kirichenko V. A., Logvinov Yu. F., Razskazovsky V. B.
38-45
The specific of cm and mm radio wave backscattering by the upper soil layer in application of remote sensing from aerospace carriers was analyzed. This specific is caused by layered soil moisture structure in depth and spatial fluctuation of dielectric constant of the surface layer of the soil. The quantity estimation for the 3 cm and 8 mm radio waves is shown. The strong influence of soil moisture change (that can be at the depth of unit of millimeters) on the backscattering is shown.
ILLUMINATED SEA SURFACE CRESTS FOR SYMMETRIC TRACES OBSERVED AT SMALL GRAZING ANGLES
Kirichenko V. A., Logvinov Yu. F.
46-54
THE FEATURES OF RADIATION PATTERN FORMATION OF THE MONOPOLE ANTENNA WITH FINITE SCREENS
Ivanchenko I. V., Korolev A. M., Pazynin V. L., Popenko N. A., Khruslov M. M.
55-60
Following the results of experimental and theoretical studies the appropriate approaches of different radiation pattern formation have been suggested and analyzed with reference to the coaxial monopole antennas. Based on the analysis of theoretical results concerning the processes of electromagnetic field formation near the antenna under study a contribution of EM fields scattered by its component elements in the radiation pattern has been shown. The antenna design proposed by us can be used as a basic one in manufacturing of the compact and effective direction finder, as well as antenna arrays.
SOME RESULTS TROPOSPHERE REFRACTION PROPERTIES ESTIMATION WITH HELP OF GEOSTATIONARY SATELLITE RADIATION
Khalameyda D. D., Khomenko S. I.
61-64
The information about research method, equipment used and data obtained of full-scale measurements at sea and land paths. The refraction properties of troposphere are estimated with help of geostationary satellite radiation “Asiasat 3S”. The analyses of measurement errors are performed and implementation errors are minimized because of rational interferometer development. The main error of troposphere refraction properties is due to quasi-periodical displacements of satellite on orbit, which are conditioned by the Moon and the Sun. Such errors can be minimized by using of data about satellite location in Internet network. The measured refraction data are compared with calculated data which are received with the help of surface refraction ratio.
DIFFERENTIAL DOPPLER VELOCITY: RADAR PARAMETER FOR ESTIMATING TURBULENCE INTENCITY
Mazura I. V., Yanovsky F. Y.
65-69
Differential Doppler velocity is a Doppler polarimetric radar parameter which combined both Doppler and polarimetric measurements. Doppler measurements enable to get information about dynamic processes in rain (raindrop velocity). Polarimetric measurements enable to get an information about droplet shape and orientation. When turbulence occurs, raindrops are involved into motion and change their velocity and orientation. Investigation of differential Doppler velocity dependence from turbulence intensity is presented in this work. Relationship between these parameters is shown theoretically with the help of developed model and is tested on raw Doppler polarimetric radar.
PRECIPITATION AND TURBULENCE INTENSITY CLASSIFICATION BASED ON DOPPLER-POLARIMETRIC RADAR DATA ANALYSIS
Ostrovsky Y. P., Yanovsky F. J.
70-73
This paper briefly describes methodology of precipitation and turbulence classification based on data retrieved by Doppler-polarimetric radar. Not only classical parameters of turbulence such as eddy dissipation rate are integrated in classification procedure but also polarimetric and parameters based on averaged Doppler velocity analysis. The complexity of this procedure and scientific importance of this task is obvious. The classification procedure based on fuzzy logic takes place after detailed processing of echo signal and informative parameters computation. This allows us to distinguish between different types of precipitation and turbulence intensities. The decision about precipitation type and turbulent motion intensity is provided by simultaneous analysis of informative parameters.
DETECTION OF ICING ZONES BY REMOTE SENSING OF METEOROLOGICAL OBJECTS
Pitertsev A.
74-77
The results of mathematic simulation of remote sensing of the meteorological objects are shown. The values of main polarimetric variables are calculated, checking has been done using the results of practical measurements. Icing detection algorithm is recommended.
INTERPRETATION OF RESULTS OF GEORADAR SUBSURFACE PROBING IN CONDITIONS OF ABSENCE OF THE PRIORI DATA
Sugak V. G., Ovchinkin O. A., Sugak A. V.
78-86
It is stated the method, allowing to raise rekiability of interpretation of results of subsurface probing at the decision of problems of the engineering geology, based on use of a numerical method of solving of Maxwell equations for an electromagnetic field in the limited space by the Finit Elements Method in a frequency area in a combination to the information received from the georadar data.
MAGNETORESISTANCE AND SPIN POLARIZATION OF ELECTRON CURRENT IN MAGNETIC TUNNELING JUNCTIONS
Beletskii N. N., Borysenko S. A., Yakovenko V. M.
87-95
The influence of the bias voltage on the magnetoresistance and spin polarization of the electron current of the ferromagnetic metal-insulator-ferromagnetic metal (FM/I/FM) tunneling junction within a two-band model of free electrons in ferromagnetic electrodes has been studied theoretically in the paper. It is shown that the value and sign of the magnetoresistance of the FM/I/FM tunneling junction depend essentially both on the height and width of the potential barrier and on the value of the bias voltage. We have found out that the height and width of the potential barrier can be chosen in such a way that the value of the magnetoresistance can be both reduced and increased as the bias voltage increases. It has been determined that the magnetoresistance changes the sign and oscillates with increasing bias voltage. We have found out that the change of the sign of the magnetoresistance takes place due to the fact that the tunneling transmission coefficient of the majority electrons is the largest in the case of the antiparallel magnetization of the ferromagnetic electrodes and not parallel one. It has been shown that the value and sign of the spin polarization of the electron current can be changed with reversing the ferromagnetic electrode magnetizations.
THREE TYPES OF SPECTRA IN ONE-DIMENSIONAL SYSTEMS WITH RANDOM CORRELATED BINARY POTENTIAL
Usatenko O. V., Melnyk S. S., Yampol'skii V. A., Johansson M., Kroon L., Riklund R.
96-100
The stationary one-dimensional tight-binding Schredinger equation with a weak diagonal long-range correlated disorder in the potential is studied. An algorithm for constructing the discrete binary on-site potential exhibiting a hybrid spectrum with three different spectral components (absolutely continues, singular continues and point) ordered in any predefined manner in the region of energy and/or wave number is presented. A new approach to generating a binary sequence with the long-range memory based on a concept of additive Markov chains is used.
DYNAMICS OF DAVYDOV’S SOLITONS IN ELECTROSTATIC FIELD
E. Natanzon Yu., Brizhik L. S., Eremko A. A.
101-105
Here we study the influence of electrostatic field on the dynamics of self-trapped states of quasiparticles in one-dimensional molecular chain. It was shown, that weak electrostatic field causes the accelerated propagation of the quasiparticle along the chain, which can explain charge transport processes in molecular systems. The dependence of quasiparticle velocity and its lifetime on field magnitude and on the other system parameters were analyzed. It was shown, that in the ring chains even at very weak fields the quasiparticle starts moving after some period of rest.
ELECTRON-WAVE MECHANISM OF SMITH-PURCELL RADIATION IN DIFFRACTION RADIATION OSCILLATOR
Khutoryan E. M., Tsvyk A. I., Nesterenko A. V.
106-119
The electron-wave mechanism of electron beam energy transformation into Smith-Purcell radiation in non-relativistic DRO type devices has been considered theoretically and experimentally. In the context of preset incident on reflecting grating electromagnetic field the directional pattern of Smith-Purcell radiation has been defined and analyzed. It is shown that directional pattern form primarily defined by dynamic parameters of electron beam (EB) which is formed by interaction of EB with grating surface diffraction harmonic field. Radiation excitation is explained by electron-wave mechanism of transformation of grating surface diffraction harmonic into space harmonic of diffraction radiation (DR). The equation of DRO open resonator excitation was constructed; solutions of the equation have been analyzed in linear approximation. The obtained results explain series of facts are visualized in experiment, specifically, the attenuation, amplification and beating of DRO oscillation.
AUTOMATED SUBMILLIMETER LASER POWER STABILIZING
Mizrakhy S. V., Kiseliov V. K.
120-123
The automated submillimeter HCN-laser (l = 0,337 mm) power stabilizing has being investigated. The designing and testing results of power stabilizing system realised on the base of microcontroller MSP430 and step driver are presented. If we use this system, laser output stability amounts to 2 % more than 2 hours, it is enough for most measurement purposes.
PROCESSES AT THE SURFACE OF DETAILS OF MILLIMETER MAGNETRONS WITH SECONDARY EMISSION PLATINUM CATHODE
Grytsayenko S. V., Naumenko V. D., Suvorov O. M.
124-129
A study of anode and secondary emission cathode surface of three-millimeter and eight-millimeter magnetrons was performed with scanning electron microscope and the electron probe X-ray microanalysis after long life tests. Nonequal surface erosion and change of surface composition were found. Possible mechanisms causing found changes has been described. The obtained results are important for solving of the essential problem of increasing of reliability and repeatability level of devices which are using in up-to-date microwave systems.
MECHANICAL FREQUENCY CHANGE OF KLYNOTRON-TYPE OSCILLATOR
Mil’cho M. V., Zavertanniy V. V., Kirichenko L. A., Kudinova T. V.
130-137
The frequency change methods for klynotron-type oscillators of millimeter and submillimetr wave bands arediscussed. The some oscillator designs and the frequency change mechanism are described. The some klynotron experimental characteristics are given.
MODELING AND ANALISIS OF 100 KW COAXIAL MICROWAVE PLASMATRON DESIGN
Sekretaryov S. S.
138-143
Using computer modeling, the influence of geometric dimensions on characteristics of wave field in microwave plasmatron has been investigated. The problem of matching of a coaxial plasmatron with large diameters and rectangular waveguide feeding has been studied. New types of coaxial-to-waveguide junctions which have sufficiently large transmission band and capable to operate with high power level have been proposed. It has been shown that the mode interference in the coaxial causes to inhomogeneous field structure in discharge chamber. The field pattern in coaxial waveguide with two propagating modes in plasmatron has been studied, and its effect on ignition of plasma has been discussed. Several types of optimal plasmatron constructions have been proposed, which are of interest of practical applications, including microwave-plasma burner for coal dust.
SPECTRAL METHODS OF SECONDARY SOURCE CHARACTERISTICS ESTIMATION IN A MULTYRAY CHANNEL
Lutsenko I. V., Popov I. V., Lutsenko V. I.
144-148
The possibility of spectral analysis employment for the determination of the signal quantity coming to the receiving point in a multipathing channel is considered in present paper. The quantity and the coordinates of the reflecting points? Their lifetimes on diffusing sea surface are tested and reflectance estimation, location height, conveying speed of elevated troposphere inversion layers are found as well with given method.
ACTIVE OSCILLATOR STABILIZED AXIAL- LAMINATED QUASI-OPTICAL DIELECTRIC RESONATOR SUCH AS CELL DI-ELECTROMETER
Krivenko E. V., Kirichenko A. Ya., Kutuzov V. N., Lutsenko V. I.
149-152
The Q-factors of eigenoscillations of axial-flaky structure consist of dielectric layer is parallel to faceplate of partially shielded half-disk dielectric resonator are investigated. Established that at carrying in the resonator field parallel to its side surface at the some sighting distance the investigated sample of dielectric leads to resonator frequency and its Q-factor change the more the values of imagine and real parts of investigated material permittivity higher. The influence of dielectric type its thickness and sighting distance on frequency and resonant Q-factor for the different oscillation types are investigated. The dependences of frequency and steepness of electron tuning of self-excited oscillator on basis of Gunn-effect diode that stabilized of axial-flaky structure change on dielectric type and thickness are obtained.
EXPERIMENTAL RESEARCH OF DISCHARGE PROCESSES IN WATER SOLUTION WITH IMPURITIES
Khorunzhiy M. O., Yefimov B. P., Kuleshov A. N.
153-157
The experimental results of the influence of electric current on weak electrolytes consist of distilled water with little quantity of impurities as salts and acids have been presented. Such weak solutions are similar to natural water. The influence of external strength (electric current) on such mediums resulted in the observation of both corpuscular and electromagnetic radiation of wide wave band including Roentgen and also plasmoid blowout in the air. There is experimental model description, electrical regimes of discharge in water medium, time characteristics of discharge process, discussion of obtained results in this paper. The fundamental review of this problem status is also given.