1999, volume 4, № 1

PHYSICAL-GEOMETRICAL INTERPRITATION OF  - CHARACTERISTICS OF ELECTROMAGNETIC FIELD

V. M. Onufrienko

7-10

The  -features for study of a behaviour of components of an electromagnetic field near to a point set with fractal properties is defined. For the definition of -features the algorithms are reduced: geometric, constructed on the definition of a measure of the Hausdorff, and analytical, constructed on application of a means of fractional derivatives and integrals. The example of a construction of a model of a fractal charge and definitions it of  -features is considered.

FORMATION OF A BEAM WITH A UNIFORM INTENSITY DISTRIBUTION IN A GENERALISED CONFOCAL CAVITY WITH A GRADED-PHASE MIRROR

O. V. Gurin, V. A. Maslov, I. M. Militinskii, V. A. Svich, A. N. Topkov

11-14

A description is given of a method of forming, in a generalised confocal cavity, beams with a uniform intensity distribution. The method is based on the use of the graded-phase mirrors. Based on the numerical calculations of the characteristics of the even-symmetric lowest-loss modes the both resonator and its graded-phase mirror geometry for the formation of such beams have been found.

EXAMINATION OF OPTIMUM SECTIONAL TAPERS FOR QUASI-OPTICAL WAVEGUIDE LINES

V. K. Kiseliov

15-19

The amplitude-frequency and polarization characteristics of optimum sectional tapers (OST) intended for the broadband coupling of quasi-optical transmission lines of class “hollow dielectric waveguide” were experimentally studied on a basis of the four-sectional model in a quite wide wave range 2,5 - 8 mm. The calculation formulas providing the OST design received their experimental verification. Keeping the broadbandness and the low level of wave depolarization of the usual linear taper, the suggested design as a sequence of truncated circular cones gives essential cut in size. And even at the few sections, the OST characteristics are close to the main characteristics of the ideal parabolic taper, whereas the OST manufacturability is much higher due to the simple geometry of the OST sections. 

REGULARIZATION OF A BOUNDARY VALUE PROBLEM FOR AN ARBITRARY SCALAR WAVE DIFFRACTION BY UNCLOSED SPHERICAL CAP. DIRICHLET’S PROBLEM

Yu. V. Svishchov, E. V. Svishchova

20-27

The diffraction problem of an arbitrary scalar wave by spherical screen with a circular aperture is considered (Dirichlet’s problem). Resonance and scattering characteristics for plane wave’s scattering case have been investigated. In particularly, the mode’s interaction effect has been discovered. 

EFFECT OF FOCUSING LIMIT IN THE MULTIFOCAL OPEN RESONATORS

A. P. Koretsky

28-32

In this paper, the resonance-focusing properties of the multifocal open resonators (MOR) are examined to determine approximately the diffraction limit of the wave focusing by using a focal parameter. The paper gives short characteristics of MOR as a new type quasioptical resonance systems; MOR with the focus number n=3 was taken as an example to demonstrate their performance. A number of experimental tests of MOR with a focal parameter decreasing in value was performed in the millimeter wavelength band. The analysis of results allows to determine approximately the range of the focal parameter values, where the effect of the diffraction limit of wave focusing is particularly pronounced, but the system still has the focusing properties.

RESONANCE-FOCUSING PROPERTIES OF THE MULTIFOCAL OPEN RESONATOR WITH AN EXTENDED HETEROGENEITY

A. P. Koretsky

33-36

The paper considers the impact of extended heterogenieties like reflecting diffraction grating (RDG) on the resonance-focusing properties of a multifocal open resonator (MOR) with a small focal parameter. It was shown that a heterogeneity “flat insert” slightly influences the resonance-focusing properties of MOR. The heterogeneity “solid RDG” changes the properties of MOR splitting and symmetrically extending its wave focuses. It was determined, that this effect can be reduced by employing flat inserts and RDG located in turns in adjoining focuses. MOR are supposed to be applied in the diffraction radiation generators.

THE RESEARCH OF CYLINDRICAL WAVEQUIDE-DIELECTRIC RESONATOR

Yu. G. Makeev, A. P. Motornenko

37-42

The electrical characteristics of waveguide - dielectric resonator with sliding short-circuit piston are investigated. The calculations and experimental researches of resonance properties of such resonator are carried out.

DYNAMIC PORTRAITS OF SPECTRAL POINTS OF OPEN PERIODIC RESONATORS (GRATTINGS) IN TIME DOMAIN

A. O. Perov

43-58

The approach based on a research of features of resolving operators (resolvents kernel) of stationary boundary value problems of the theory of a diffraction of waves on grattings, is used for the analysis of a number of legitimacies appearing with creation of resonance responses of such structures on energization by their nonsinusoidal waves.

SHIP DETECTION BY SHADOW ON THE SEA

I. S. Turgenev, S. I. Khomenko, A. E. Zatserklyany

59-62

The possibility of the ship detection by shadow on the sea surface was considered. The approximate relations permitting to define visibility of shadow on a hum noise of reflections from the sea depending on the characteristics of radar and objects are obtained.

OBSERVATION FOR THE WORLD THUNDERSTORM ACTIVITY MOVEMENT BY THREE COMPONENT SCHUMANN RESONANCE MEASUREMENTS

G. G. Beliajev, A. P. Nickolaenko, A. V. Shvets, A. Yu. Schekotov

63-69

Schumann resonance measurements have been performed at Lekhta (Karelia, Russia) during July-August of 1998. Three field components were synchronously measured. These are a vertical electric and two orthogonal horizontal magnetic components. Processing methods based on calculation of the second integral moments of the spectral field components were used for pelengation of the world thunderstorm centers and estimation of their diurnal activity dynamics. An existence of a night (2-3 UT) maximum of the African thunderstorm activity, which is of about one third of the main day maximum activity, had been discovered.

CASIMIR EFFECT IN THIN METAL FILMS

V. N. Dubrava, V. A. Yampol'skii, O. I. Lyubimov

70-76

The role of the dispersion properties of thin metal films in the formation of the force of their Casimir attraction is theoretically studied. The case of low temperatures, when the interaction between the films is basically formed by the vacuum fluctuations of the electromagnetic field, is considered. A closed analytical equation for the Casimir force as a function of the film thickness d, a distance a between the films, and a skin depth d at some characteristic frequency is obtained. Asymptotic expressions of the Casimir force corresponding to frequency regimes of the normal and infra-red skin effects are derived for the thin films with d<<d . The principal opportunity of the study of the electron characteristics of the films by measurements of the Casimir force is demonstrated.

GENERATION AND AMPLIFICATION OF ELECTROMAGNETIC OSCILLATIONS BY A TUBE-SHAPED BEAM OF PLASMA IN CROSSED RADIAL ELECTROSTATIC AND AXIAL MAGNETIC FIELDS IN FREE SPACE

Yu. V. Kirichenko

77-79

A possibility of a electromagnetic wave generation and amplification by plasma rotating in crossed axial-magnetic and radial-electrostatic fields in free space has been investigated by theory. A dispersion equation describing the wave-electron interaction is derived. It is demonstrated that radiation generation can occur under Cherencov resonance conditions.

ON SOME SPECTRAL PECULIAR OF SPARK DISCHARGE

A. D. Yegorov, A. P. Motornenko, V. P. Pelipenko

80-82

Optical spectra of spark high-frequency emission between the copper electrodes at atmosphere pressure. The impurity lines are detected and an increase of their intensity with a decreasing oscillation period and in the initiation of laser-emitted spark discharge have been stadied. 

A MODIFIED COUNTER-SWEEPS METHOD

K. A. Lukin, P. P. Maksymov

83-86

A new counter - sweeps method for a numerical solution of the drift-diffusion equations for semiconductor structures with p-n junction is suggested. Solutions for a silicon semiconductor structure are presented as examples of the method application. Solutions of Poisson equation obtained showed a high accuracy and stability of the modified counted-sweeps method.

A METHOD FOR SEMICONDUCTOR STRUCTURE WITH ABRUPT p-n JUNCTION SIMULATION

K. A. Lukin, P. P. Maksymov

87-92

A new method for numerical evaluation of semiconductor structures with an abrupt p-n junction is presented. The algorithm of the method is based upon the modified counter-sweeps method, that provide automatically continuity of electric field at the interface of p- and n- areas. The method suggested unlike known methods provides the algorithm that is highly stable with respect to variation of the structure parameters, such as doping, ets. 

SURFACE POLARITONS IN A FINITE WEAKLY DISORDERED SUPERLATTICE PLACED INTO THE QUANTIZING MAGNETIC FIElD

N. N. Beletskii, J. V. Bludov

93-102

The paper deals with the theoretical investigation of surface polaritons (SP) in a weakly disordered superlattice (WDSL), formed of the finite number of infinitely extended two-dimensional electron systems (2DES), arranged on the equal distance from each other and placed into the external constant quantizing magnetic field, directed perpendicularly to 2DES. The WDSL is characterized by the fact, that the Landau-level filling factor of one 2DES (singled 2DES) was different from the value of Landau-level filling factor of other 2DES. At the same time it is supposed, that the singled 2DES can occupy an arbitrary position in the WDSL. The dispersional and energy properties of SP in the finite WDSL is investigated in the case when WDSL is placed in the uniform dielectric medium and in the case when it is placed on the substrate and verges on the vacuum/air. It is shown that under the integer quantum Hall effect (IQHE) conditions all characteristics of the SP are represented by the quantized values. It is found, that in the finite WDSL the SP local mode exists, which properties differ from the properties of the SP usual modes in the finite ordered superlattice. It is defined, that the spectrum of the SP usual modes is very sensitive to the position of singled 2DES in the finite WDSL and the spectrum of local mode of SP are weakly sensitive to the position of singled 2DES. The conditions, under which the phase and group velocities of the SP in the finite SL under certain conditions can be considerably less than the phase and group velocities of the SP in the isolated 2DES, is defined.

TRANSITIONAL PROCESSES IN HCN-LASER PLASMA

Yu. E. Kamenev

103-105

The step-line change of a plasma conductivity at the movement of laser generation has been observed in electro-discharge HCN-laser. The pumping has been produced by pulsing discharge current with frequency of 100 Hz. The investigation of cathode shape influence on characteristics of a laser discharge was carried out.

MICROWAVE OSCILLATOR WITH THE SHIELDED QUASIOPTICAL DIELECTRIC RESONATOR

A. E. Kogut, V. K. Korneenkov, V. I. Lutsenko, S. N. Kharkovsky

106-109

The Gunn oscillator with partially shielded hemidisk quasioptical resonator is investigated experimentally at this paper. The investigations of the generation characteristics of oscillations by the semiconductor diode in this resonator are carried out for the different radial co-ordinates of the oscillator active element. The advantages of the investigated oscillator at comparison with the oscillator with open dielectric resonator are shown.

60-65 GHz BEND DOUBLE-CIRCUIT PARAMETRIC AMPLIFIER

A. P. Kasyanenko

110-113

Noncooled low-noise parametric amplifier designed for using as input stage of 60-65 GHz bend receiving devices.

MILLIMETER-WAVE BAND TWT

A. P. Kasyanenko

114-116

The resalts of the development of the millimeter wave band TWT of average power with the double ladder slowing- down system in the crociform wavegoide.

THE ELECTRON BEAM MODULATION FOR THE FREQUENCY MULTIPLICATION WITH THE LARGE FREQUENCY RATIO

M. V. Mil’cho, B. P. Efimov

117-124

The electron beam modulation process in resonators with the volume distribution of HF fields, which is closely approximated to the real distribution, has been analysis. Conditions, which allow to form electron bunches for the frequency multiplication with a large frequency ratio, has been specified.

DERIVING THE RESULTS OF RECORDING LUMINOUS FLUXES OF DIFFERENT INTENSITY IN NOISE IMAGES WHEN OBSERVING POINT RADIATION SOURCES

Yu. G. Danyk

125-128

A method of deriving an image of aggregate point objects from a sequence of images being subject to the influence of the internal noise of a matrix light sensor. The efficiency of the method has been estimated through theoretical analysis, statistical simulation and experimental checking. An expression for the optical transfer function for the case of weak light flutes has been deduced.

VERY HIGH FREQUENCY DIELECTROMETER FOR STUDYING DYNAMICAL PROCESSES IN DISPERSE WATER SYSTEMS

S. V. Gatash

129-132

The functional scheme of the equipment for studying fast dynamical processes in water suspensions and solutions has been presented. The equipment includes 3 cm range VHF dielectrometer of resonator type, optical measurement system, unit for synchronization and operation of measurement regimes. The data of measurements of dielectric constant ’ and optical density of platelet aggregation in blood plasma have been presented to illustrate the possibilities of the method and equipment suggested.