2003, volume 8, ¹ 1
THE NUMERICAL ANALYZE OF NEAR FIELDS FOR RADIATORS OF NONSINUSOIDAL WAVES
Vyazmitinova A.I., Sirenko Yu.K.
7-16
In this work were presented the results of numerical investigation interaction’s processes between pulse-electromagnetic fields and objects. In this paper were considerate the effects, which have to be taking into account for effective synthesis of radiators of nonsinusoidal waves and advanced, which is orientated on analyze parameters of single electromagnetics pulses.
DIFFRACTION EFFICIENCY OF THE SECOND ORDER BRAGG DIFFRACTION COMPONENT DURING THE INTERACTION OF LIGHT WITH ULTRASONIC WAVE IN SINGLE-AXIS CRYSTALS
Cherkashina E.L.
17-21
The continuous fractions method was used to obtain analytical expressions for the first order Bragg diffraction components during the interaction of light with cross-sectional ultrasonic wave in single-axis crystal at a double Bragg angle. It was established that diffraction efficiency value of the second order component depends both on optoacoustic interaction parameters and optical wave polarization direction as well as on crystal properties.
A MODEL FOR MILLIMETER- AND CENTIMETER-WAVES FIELD OVER A SEA SURFACE DESIGN FOR INVESTIGATION THE METHODS FOR LOW-FLYING TARGETS ELEVATION ANGLE MEASUREMENT
Razskazovskiy V.B., Pedenko Y.A.
22-33
The problem of modeling the millimeter and centimeter radio wave field over rough sea surfaces at grazing angle propagation is reviewed. On the basis of the analysis madeusing the published data, a model of the field has been evolved as applied to the study of the method intended for radar measurement of low flying target elevation. Approach to the choice of the model parameters has been proved, including the distribution of diffuse reflections with the distance under conditions of sea surface area shadowing by wave’s edges. The approach to correcting the bistatic scattering coefficient has been offered to achieve the diffuse reflection coefficient consistent with those observed in nature experiment. The designed model of the field was used at the computer-based simulation of the radar elevation meters. The results obtained with its help are close to those obtained in real conditions on sea.
STATISTICAL CHARACTERISTICS OF SEA SURFACE AT SMALL SLIDING ANGLES FOR BACKWARD RADIOWAVE SCATTERING
Logvinov Yu.F.
34-41
The distributions of heights, lengths, inclination and radii of curvature of the lit up areas of sea surface have been obtained using the computer modeling method, as applied to the backward scattering problem.
ÒHE SPATIAL STATISTICAL CHARACTERISTICS OF EARTH SURFACE
Kulemin G.P., Tarnavsky E.V.
42-47
The spatial statistical Earth characteristics are analyzed. It's a necessary for aerospace remote sensing explanation of Earth surface. The research results are needed for the radar map modeling. Àbility of a separate description by means both micro and macro relief is showed. The spatial earth surface spectra can be defined by fractal. The local slope distribution is close to the Gaussian law.
A SAR IMAGE ADAPTIVE CORRECTION ALGORITHM
Sytnik O.V.
48-54
The problems of construction of adaptive algorithms of synthesizing the radar-tracking images of sub-surface layers by the signals of coherent onboard radar are considered. The offered algorithm concerns a class of self-adapting algorithms in which the information about the trajectory mistakes is taken directly from the reflected signal. The Doppler spectrum displacement value in the interval of synthesizing averaged over the inclined range and its derivatives of the higher order are used as the information parameters. This provides a possibility of correcting automatically the images whose distortions are caused not only by mistakes related to carrier’s flight velocity but also by those brought about by the neglected acceleration and acceleration change velocity. The results of signal processing of coherent radar with the aerial aperture synthesizing (AAS) are given. The features of the work of the algorithm in various conditions are discussed.
COMPUTATION OF ELECTROMAGNETIC RESONANCE IN THE EARTH-IONOSPHERE DUCT BY USING A FULL-WAVE AND A SIMPLIFIED MODEL
Jones D. Llanwyn, Knott M.
55-66
A method is described for the application of the two-scale-height ionosphere model [1] to an arbitrary conductivity profile. The simplified model is used to calculate the frequencies and Q-values of the Schumann resonance for the Cole-Pierce profile [2]; the frequencies predicted are found to be in agreement with exact theoretical treatments, but the frequency dependence of Q-factors is too steep. It is also concluded that theoretical predictions using the Cole-Pierce profile do not agree with experimental measurements. The model is applied to a range of profiles, and successfully predicts the resonance frequencies even when it was previously thought not to be valid. However, the predictions for the Q-values are generally poor.
AN ANTENNA SYSTEM OF A CONTINUOUS WAVE RADAR
Andrenko S.D., Vyazmitinov I.A., Sidorenko Y.B.
67-71
The given work describes an antenna system of a continuous wave decimeter radar. The transmitting and receiving antennae are cylindrical spirals with the oppositely directed windings, where the distance between the axes is comparable with the wavelength. The main antenna parameters have been experimentally determined. It is shown that the reception-transmission channel isolation coefficient is 75-80 dB in the frequency band ranging +18% relative to the central value.
THE DOPPLER SPECTRA OF MICROWAVE BACKSCATTERING BY SHIP WAVES
Gorobets V.N., Gutnik V.G., Kivva F.V.
72-77
New experimental results on the problem of microwave backscattering by ship waves, mainly in terms of Doppler spectra are considered. A model of backscattering when in good agreement between theoretical and experimental results is presented. It is shown that different characteristics of backscattering signals are determined by the velocity of target.
SETUP FOR MEASUREMENTS OF PARAMETERS OF SEMIMAGNETIC SEMICONDUCTORS BY ELECTRON SPIN RESONANCE METHOD
S.Yu. Karelin
78-85
Setup for measurements of parameters of semiconductor solutions by ESR method and some results of measurement of semimagnetic semiconductors Cd1-xMnxTe with manganese concentration from 0.1 to 0.45 are presented.
SATURATION OF STATIONARY INVERSION STATES IN A RUNNING-WAVE QUANTUM AMPLIFIERWITH BISTABLE RESONATOR PUMP
Makovetskii D.N.
86-98
The inversion states of a saturated three-level running-wave quantum paramagnetic amplifier are investigated under conditions of bistable resonator pump. The equations of motion for the vectorial order parameter are obtained using adiabatic elimination of fast variables. These equations present a generalization of the scalar two-level Drummond's model for the case of three-level quantum active system. Isolated branches of inversion ratio are revealed from stationary solutions of vectorial order parameter equation. A detailed analysis of bifurcations in saturated quantum amplifier with bistable pump is presented.
TEMPERATURE CONDITION STUDY OF STARTING CATHODE IN MILLIMETER MAGNETRON
Naumenko V.D., A.N. Suvorov, A.R. Syrov
99-101
The temperature conditions of starting cathode in millimeter magnetron at its different operation modes is researched in the work. The widespread opinion, that installed outside interaction space starting cathode is not undergoed to back bombardment, is not confirmed in practice. Power scattering on this cathode may reach 1–2 and more percent of brought power. It is essentially lower than power scattering on main cathode, but it must be taken into account definitely to avoid life shortening when working with large duty factor. It is demonstrated in the work that even at anode current equel 10–20% of working current there has been a sharp increase in temperature of starting cathode. The value of this jump depends on the form of a pulse of an anode voltage. Than more duration of front and decay of a pulse, the more power, scattered on the starting cathode. Knowing temperature of the cathode necessary for stable work of magnetron, has appeared possible to measure true current density of the starting cathode. For present magnetron it has appeared equal approximately 1 À/ñm2. The knowledge of this size has allowed also further to put work at the choice of a type of the starting cathode for magnetron with large durability.
ELECTRICAL AND SPECTRAL ACCORDANCE IN LAMP-PUMPING SYSTEMS OF PULSE LASERS
Shevchenko V.V.
102-109
There was study the influence of the most important factors both on efficiency and useful life of flashlamp-pumped systems of pulsed lasers. The features of operating of these systems were considered for different parameters of impulses. The technique of design of effective flashlamp-pumped systems is offered.
OPERATION OF COMBINATION OF TWO LEVEL RESONANCE TUNNELLING AND GUNN DIODES
Botsula Î.V., Prokhorov E.D.
110-114
The operation of series - connected two level AlAs/GaAs resonant tunnelling diode and Gunn diode in resonance circuit are considered. The current - voltage (I-V) characteristic such diodes combination have particularities: current jump, unmeasurable region of current - voltage characteristics, shift of current maximum to larger voltage. The I-V characteristic have three region of negative differential conduction ca be used for generation in millimeter wave range. The correlation Gunn diode’s parameters and resonance tunneling diode’s parameter lead to three oscillation region are determined. The oscillation efficiency in this region are determined.
ULTRA-HIGH FREQUENCY INTENSE PULSE ELECTRON SOURCES
Ayzatsky M.I., Khodak I.V., Kushnir V.A, Mitrochenko V.V., Zhiglo V.F.
115-119
The paper concerns the experimental research of the ability to generate intense pulse electron beams in S-band radio-frequency guns (RF guns) utilizing metal-dielectric cathodes. Results of calculations and design of the cathode experimental sample are described. Results of the experimental research of the RF gun operating modes are reviewed. The beam at the gun output has the pulse current of 3.5-4.5 A with the current pulse duration of 40-50 ns and with particle energy of 300 keV.
VACUUM STATE INVESTIGATION OF CROSSED-FIELD DEVICES. BY DISCHARGE CURRENT
Zin’kivski V.M., Nikitenko O.M.
120-126
The discharge current method was used to measure pressure into two electrode crossed-field devices. The theoretical and experimental performances were shown to measure vacuum state into such devices. The boundaries were defined to use this methods to measure pressure.
MODELING OF THE PULSE OPERATING MODE OF A LASER WITH PHOTOTROPIC Q-SWITCH IN THE CONDITIONS OF RESONANT INTERACTION OF THERMAL NOISE WITH THE MODULATING MEDIUM SUBSTANCE
Bykov M.M., Dzybenko M.I., Rudchenko I.M.
127-130
The modeling of the pulse operating mode of a laser with phototropic Q-switch in the conditions of thermal noise processes in the modulator has been carried out. The dependences of pulse radiation characteristics on the value and dispersion of noise have been analysed.
A WAVEGUIDE SUBMILLIMETER LASER WITH MODE SELECTOR
Gurin O.V., Degtyarev A.V., Maslov V.A., Svich V.A., Tkachenko V.M., Topkov A.N.
131-135
An optically pumped submillimeter laser on a basis of the quasioptical waveguide resonator with mode selector is investigated experimentally. It is shown that the proposed method for the selection of transverse modes by an iris diaphragm on the plane mirror of a system of deflecting mirrors allows one to ensure the effective suppression of higher oscillation types by operation of a laser in a wide spectral range.
THE CONFORMAL MAPPING MÅTHOD FOR ANALYSIS OF HIGH FREQUENCY ELECTRO-MAGNETIC FIELDS OF SLOW-WAVE STRUCTURESCH. 1. THE LARGE SLOW-DOUN CASE
Mil’cho M.V.
136-147
The numerical-analytical method for the analysis of the high-frequency fields of eigenmodes of slow-wave structures which are composed of metal rectangular elements is described. These systems are gratings, combs and other similar constructions. The field distribution for the concrete slow-wave structure is presented in the form of a linear combination of several solutions to the problems of wave diffraction on a periodical structure which consists of the finite-thickness half planes. The solution of these auxiliary diffraction problems is found from the requirements of identity of the combined functional equations for electrodynamic and electrostatic problems. The exact solution of electrostatic problems is obtained by the conformal mapping method. Formulas for the electrodynamic fields calculation are obtained in a closed form. All space harmonics of the field are taken into account. The fields singularities near the sharp edge of metal elements are correctly described. In the first part of the paper a large slow-down approach is described when all space harmonics wavelengths are much less than the vacuum wavelength. Space-time variations of fields graphs are presented for the comb structure.
EFFECT OF ELECTROMAGNETIC LINEARLY AND CIRCULARLY POLARIZED WAVES ON THE IN-CELLULARLY NUCLEUS ELECTROPHORESIS OF HUMAN CELLS
Grigoryeva N.N., Sirenko S.P., Shakbazov V.G., Fisun A.I., Belous O.I., Gorobets N.N., Kiyko V.I., Grabina V.A.
148-155
The influence of electromagnetic radiation (EMR) of J-, K-, and L-bands on the in-cellularly nucleus electrophoresis was investigated. The left-handed, clock-wise and linearly polarized waves had been used in experiment. Index of the electronegative nuclei (ENN) or %-% negatively charged nuclei, shifting to anode in a specially constructed chamber as well as the power and frequency dependences was the key parameters of the influence. All changes of ENN occurred due to radiation were compared to the age norm (AN) which takes into account an average statistical index obtained previously for relatively healthy people. Trials were carried out using cells belonging to 4 female donors of various age (ranging from 21 to 51 years old). The findings showed that EMR of EHF and SHF band results in changes in ENN index, within this, the right polarized waves were more effective compared to linear and left polarized ones. Character and amount of changes of ENN depend on the index control value and they do not depend on the age of a donor providing cells, frequency and density of power flow of EMR. Decrease of the index at radiation normally occurs in cases when control exceeds AN. Index growth is observed within low control values in relation to AN. Evidence on the normalizing influence of a low intensive microwave radiation on the ENN index obtained previously are confirmed.
QUASI-OPTICAL SECTIONAL WAVEGUIDE TAPER FOR SUBMILLIMETER WAVE BAND
Kiseliov V.K., Mizrakhi S.V.
156-158
The results of development and researching of the sectional waveguide taper (SWT) intended for mating quasi-optical tract executed on the basis of transmission line in the kind of “hollow dielectric waveguide” (HDW) with wideband optical-acoustics receiver (OAR) have been presented. SWT ensures transmission of electromagnetic energy from HDW to OAR in a broad band frequencies 600 - 900 GHz with small enough losses at essential (up to 23%) reduction the length of taper comparatively with appropriate linear taper at saving manufacturability and lowcost.
ORIGIN OF THE HIGH ENERGY MICROWAVE ELECTRONICS IN KIEV
Kasatkin L.V., Rapoport G.N., Taranenko V.P.
159-162
The basic results of investigations and developments of microwave sources with continuous power level 5 kW and the frequency range 10% at the wave lengths l < 3 cm that were fulfilled in 1945-1960 in Kiev's Politechnicalal Institute and Laboratory of high frequency currents at Electrotechnic Institute of Academy of Science of USSR, are discussed. These works were performed under the guidance of professor S.I.Tetelbaum. Many important problems were solved in that 15 years, that gave the start for development of high power, broadband isochronous and backward wave generators with longitudinal interaction. For the first time the conditions of effective interaction of periodic electron beams with fast waves and the first working models of such oscillators were created. For the first time the systems for spatial power combining with sources located on the integrant surface (polygenerators) were proposed and investigated.