2005, volume 10, ¹ 3
OPEN RESONATORS WITH TWO CONDUCTIVE CYLINDRICAL INSERTS
Melezhik P. N., Miroshnichenko V. S., Senkevich Ye. B.
351-356
The researches of the H-polarized mode properties in the two-dimensional open resonator (OR) with two conductive cylindrical inserts are carried out. It is found and investigated the effect of increase on 1,5-2 order of diffractive Q-factor for the fundamental mode due to conductive inserts with a diameter, which it is sufficient for constructive accommodation in active elements OR and their cooling. The opportunity of the OR frequency tuning with two conductive inserts on the fundamental mode in a wide frequencies range is shown. Comparison of results of electromagnetic modeling with experiment is carried out.
OWN REGIMES OF ELECTRODYNAMIC SYSTEM CONSIST OF DIELECTRIC LAYER AND RIBBON DIFFRACTION GRATING
Sidorenko Yu. B.
357-363
It was researching a task about dissemination of own electro-magnetic waves along planar dielectric waveguide (PDW), electrodynamics connections with ribbon diffraction waveguars grating (RDG). Calculated dependence of constants of spreading in dependence of parameters of system for the lowest types of waves are represented. Amplitude allocation of components of fields in transverse sections are calculated and built. It is showed, that in electrodynamics system PDW – RDG exist own regimes of propagating surface waves, localization in the plane of diffraction grating. It is proved the existence in system of wave’s hybrid type, like this. It is the region of frequent parameter, in which is springing up strong electrodynamics connections of system with a free space.
TEMPORAL VARIABILITY OF CM AND MM SOIL BACKSCATTERING
Kulemin G. P., Kirichenko V. A., Logvinov Yu. F.
364-370
Experimental normalized radar cross section of soil without vegetation at grazing angles near 60° was shown. Experiment was fulfilled with variation of soil roughness and moisture that was controlled by contact technique. It was shown that surface scattering is dominated at the case of radio wave scattering by soil surface.
STATISTICAL CHARACTERISTICS OF SOIL IN REMOTE SENSING APPLICATIONS
Kulemin G. P., Kirichenko V. A., Logvinov Yu. F.
371-375
Contact measurements of soil roughness for agricultural fields with different tilling are shown. Emphasized that fractal description of rough surfaces is useful for the remote sensing tasks. Using a bulk of experimental data shown that exponential approximation is suited for rough surfaces and Gauss approximation is suited for smooth surfaces.
INTERFERENCE EFFECTS ON THE TROPOSPHERE MICROWAVE LINE-OF-SIGHT LINKS
Zamarajev V. B., Sinitsky V. B.
377-385
One of the possible mechanisms is considered of signal fading in a line-of-sight radio link, namely the multipath propagation due to reflections from tropospheric layers with an inverted run of the refractive modulus. A ray-optical analysis of the model troposphere with a segmented-linear N-profile has been employed to determine the spatial pattern of rays and caustic surfaces. For the case equally elevated transmitter and receiver dipoles direct formulas have been obtained allowing calculation of arrival angles and time delays along the different paths. The field amplitudes are calculated according to the "modified” ray optics which remains valid near a simple caustic too.
TROPOSPHERE REFRACTION VARIATIONS OVER THE SEA. JOINT MEASUREMENTS ON STATIONARY AND SATELLITE PATHS
Zamarajev V. B., Kabanov V. A., Morgun G. M., Sinitsky V. B.
386-393
The results of experimental researches of refraction characteristics in a near-water layer are discussed. Refraction experiments are carried out by different methods: determination of refraction angles from signals of GPS satellites setting over the sea and evaluation of decimeter wave signal path loss in a penumbra zone. It is shown that correlation of the specified parameters in separate experiences has the order 0.6 and increased for smoothing the initial data and their mutual displacement.
DESCRIPTION OF ONE METHOD OF MEASURING OF PHASE DISTRIBUTION IN MM RANGE EMITTERS
Provalov S. A., Andrenko S. D., Dudka V. G., Svischev Yu. V.
394-398
We deal with the problem of measuring of phase distribution in range emitters on basis of the principle of the volumetric (signal) wave holography and heterogenic flat (pole) wave holography. There performed test measurements of phase characteristics of emitters in their compare with general physical ideas and with the results of calculations. Here are given some practical recommendations concerning the use of described methodics in physics and techniques of mm wave range.
SCHUMANN RESONANCE MODELING BASED ON OPTICAL TRANSIENT DETECTOR ORBITER DATA
Nickolaenko A. P.
399-412
Model computations are presented of the spectra global electromagnetic resonance (Schumann resonance) in the isotropic Earth – ionosphere cavity by using the monthly maps of the worldwide distribution of thunderstorms collected by the OTD satellite. To obtain diurnal and seasonal variations of the signal, the masks were applied activating the definite parts of global lightning activity and moving around the planet. Three types of masks were used: the first one triggers the activity at the dayside of the globe («Day-side» or DS0-model). The seconds one activates thunderstorms in the afternoon sector («Afternoon» or AN-model), and the third one switches on the strokes within a circular spot of a given radius («Spot» or HS-model). Computations were performed demonstrating that numerical models developed help in studying and interpreting the Schumann resonance data. Special comparison was carried out of the model and experimental data.
INFLUENCE OF SUPERFICIALLY-ACTIVE SUBSTANCE ON AZIMUTH PROPERTIES OF SPECTRUMS OF SIGNALS OF THE CENTIMETER AND MILLIMETER RANGES BACK SCATTERING BY WATER SURFACE
Uzlenkov A. V., Lutsenko V. I., Pavlenko V. F.
413-421
Influence of film of superficially-active nonsolute on azimuthal properties of Doppler spectra of signals of centimeter and millimeter ranges back scattering by the disturbed water surface in natural terms is experimentally appraised. Possibility of these effects use for the detecting of superficially-active substances is examined.
INTRASUBBAND PLASMONS IN A FINITE ARRAY OF QUANTUM WIRES, WHICH CONTAINS A DEFECT
Bludov Y. V., Shramkova O. V.
422-427
The paper deals with the theoretical investigation of plasmons in weakly disordered array of quantum wires, consisting of a finite number of quantum wires, arranged at an equal distance from each other. The array of quantum wires is characterized by the fact that the width of one defect quantum wire was different from that of other quantum wires. At the same time it is assumed that defect quantum wire can be arranged at an arbitrary position in an array. The increasing of the local plasmon mode frequency with the decreasing of the defect QW width is predicted. We point out that when the defect quantum wire is arranged inside the array, the plasmon spectrum contains modes, the frequencies of which do not practically depend upon the defect quantum wire width.
ANALYTICAL METHOD INVESTIGATION OF ELECTRODYNAMICS PROPERTIES PERIODIC STRUCTURES WITH MAGNETIC LAYERS
Vytovtov K. A., Bulgakov A. A.
428-434
The periodic structure containing ferrite layers and isotropic stratified structures is considered. The translation matrix for a period and the transformation matrix for m of periods are written. It is shown, that the determinant of the transformation matrix is an important energy characteristic of a medium. The conditions of existence of periodic waves in structure are found. The conditions of existence of periodic waves are found in case of double-layer period (ferrite layer – isotropic layer), at which the the parameters of a gyrotropic layer do not affect on conditions of wave propagation.
PECULIAR FEATURES OF KLYNOTRON-TYPE OSCILLATOR PERFORMANCES
Mil’cho M. V., Yefimov B. P., Zavertanniy V. V., Goncharov V. V.
435-440
The peculiarities of klynotron-type oscillator performances and slow-wave structure characteristics which are used in klynotrons are discussed. The conditions ensuring the optimal klynotron operating mode are determined on the basis of experimental research. The methods for designing the slow-wave structure for the mm-wave band klynotron described.
MODELLING OF ELECTRIC OSCILLATIONS IN SPIRAL EXPLOSIVE GENERATORS
Soshenko V. A., Sytnik O. V.
441-447
In work researches of a class spiral radio-frequency explosive-driven magnetic-flux-compression generators (MCG) which basic advantages in relation to other types of similar devices is their compactness, simplicity of a design, autonomy and high power consumption are carried out. The analysis of various designs spiral MCG is executed on the basis of the developed specified equivalent circuits and mathematical models MCG. In particular, are investigated MCG with capacitor and two-tanks loadings, and also with loading as two-tanks system with nonlinear connection on the ferrite core. In models the factors, generated currents influencing amplitudes and voltage and on spectral characteristics of electromagnetic fields are taken into account. Mathematical models are submitted as systems of the differential equations with variable factors in which are taken into account skin-effect, losses of energy because of short circuit in the liner, losses on resistance of a spiral and transitive contacts. Conditions at which there is a failure of an oscillatory mode and transition of the generator in aperiodic mode are received. Calculations time and spectral characteristics of signals are executed. It is shown, that presence of the liner in designs of generators worsens their characteristics and does not allow to get signals on frequencies from above 100-150 MHz. Presence of the ferrite core in two-tanks MCG results in insignificant expansion of a spectrum of generated signals. Introduction of an arrester in a circuit of loading allows to raise a frequency range up to 300 MHz. It is proved, that the greatest energy of generated signals in such generators is concentrated in frequency a strip from 20 - 80 MHz. Methods of increase of capacity and frequency of generated fluctuations are investigated. In particular, it is offered to use in designs MCG nonlinear elements and elements with the distributed parameters. Are discussed original shematic and constructive decisions MCG.
ON CAUSES OF NOISES IN CROSSED-FIELD DEVICES
Gritsunov A. V.
448-459
The causes of noises in both the static and the dynamic states of the crossed-field devices (CFDs) are investigated with numerical experiments. In the static state those are: the tangential eigenmodes of the electron cloud; the secondary-emission bunching of the hub; the solitons in the electron beam. In the dynamic state those are the transient and the stable convective clouds in the electron spokes. An influence of the abovementioned instabilities on the electron beam oscillation spectra in CFDs is considered.
HIGH-EFFICIENCY POLYHARMONIC FIFTH-HARMONIC PEAKING POWER AMPLIFIER
A. N. Rudiakova, V. G. Krizhanovskii
460-465
The using of two-period PBG structures with Ï-shaped holes at the microstrip line’s ground plane for the obtaining of optimal amplitude and phase relations in the microwave polyharmonic power amplifiers was proposed. Considered two-periods structures have the better characteristics comparing with single-period variants in the both pass and stop bands. The theoretical and experimental investigations were conducted for the three PBG-structure variants – with square, rectangular, and Ï-shaped holes. The results show the advantages of two-period PBG-structures’ utilizing as the output filters of fifth-harmonic peaking amplifiers.
NONSTATIONARY SPATIAL STUCTURES, SLOW TRANSIENT PROCESSES AND MULTISTABILITY UNDER WEAK DIFFUSION OF EXCITATIONS IN DISTRIBUTED NONEQUILIBRIUM SYSTEMS WITH THREE-LEVEL ACTIVE CENTERS
Makovetskii D. N.
466-475
Self-organized spatio-temporal structures are numerically investigated in distributed class B active (excitable) systems. Birth, evolution, interaction and decay of rotating spiral waves (RSW) are studied in the framework of generalized Wiener-Rosenblueth model. Slowing down of transient processes caused by RSW evolution is revealed. Multistability of coherent RSW is demonstrated. Transient spatio-temporal chaos is observed in excitable three-level medium under absence of coherent RSW.
POSSIBILITY OF DISK QUASIOPTICAL DIELECTRIC RESONATORS APPLICATION FOR SMALL VOLUMES WATER SOLUTIONS INVESTIGATION
Gubin A. I., Lavrinovich A. A., Cherpak N. T.
476-481
Experimental investigation of disk quasioptical dielectric resonators with two-component water solutions filled capillary was performed. Ethanol and acetone were chosen as the second components of the solutions. Good correlation of experimentally investigated eigen frequencies and quality factor dependencies on water concentration in ethanol-water solution peculiarities with calculated dependencies of dielectric permittivity was shown. The measurements were performed in Ka waveband using whispering gallery mode dielectric resonator. The resonator could be used as a main part of a device for small volumes solutions investigation.
ERRORS OF COMPLEX DIELECTRIC PERMITTIVITY MEASUREMENT BY THE METHOD OF OPEN-ENDED COAXIAL LINE
Ivanov V. K., Silin O. O., Stadnyk O. M.
482-489
Errors of complex dielectric permittivity of lossy media measurement by the method of open-ended coaxial line due to not complete adequacy of mathematical models for real probe geometry and its location in relation to media under test are studied.