EIGENOSCILLATIONS AND RESONANCE PROPERTIES OF ONE-DIMENSIONAL METAL BAR GRATINGS. PART I. CLASSICAL GRATING
Perov À.Î., Kirilenko À.À., Senkevich S.L.
At present the resonant properties of perforated metal gratings are of interest caused by the study, interpretation and possible practical use of the «enhanced transmission phenomena». The goal of this work is the analysis of the one-dimensional periodic grating properties based on the V. P. Shestopalov school works, i.e. the study the oscillation spectra, the spectra formation principles defined in particular by the structure of the grating period and then the analysis of the spectra impact on the resonance characteristics. H-wave scattering peculiarities on one 1-D metal bar grating are considered. Resonant behavior treatment is based on open periodical resonator spectral theory. Spectrum classification is introduced for classical and compound gratings. Low eigenoscillations spectrum of classical grating as function of geometrical parameters is investigated, and eigenfrequency movement on multi sheet Riemann surface depending on grating thickness is analyzed. It is shown that limit positions of antisymmetrical eigenfrequencies are Floquet mode grazing points and the more field variation of the eigenoscillation is, the higher Floquet mode number is. Eigenfrequency paths on high Rieman sheets and the peculiarities of crossing real axis are studied. Resonance behavior of grating is described from a unified standpoint of spectral theory, which allows not only to determine the relationship between different resonant phenomena, but also to determine the root cause of such behavior caused by the excitation of certain oscillations.
WAVEGUIDE-DIELECTRIC RESONATOR WITH RESONANCE SHORT-CIRCUIT PLUNGER
Motornenko A.P., Scuratovskiy I.G., Hazov O.I.
Resonance structures of the waveguide-dielectric type are the matter for the scientific investigations contributing to the development of the resonators of new modifications with the improved parameters. The waveguide-dielectric resonators (WDR) with the short-circuit plunger have widespread application due to the wide band of the frequency tuning. But the eigen Q-factors of the oscillations in these resonators are lower than calculation ones because of the unreliable contact between the plunger and the waveguide. In this paper the use of the resonance short-circuit plunger in the WDR for the Q-factor increase of the resonance oscillations are substantiated. The characteristics of the H111-oscillation in the WDR for 3-cm band with resonance short-circuit plunger and the simple design short-circuit plunger are investigated. The resonance characteristics of the eigen frequency and Q-factor for the fundamental oscillation of the H-type for the two models of the WDR as a function of short-circuit plunger location are compared. The Q-factors obtained with the help of resonance short-circuit plunger agree closely with calculation values.
GENERALIZED MODE-MATCHING TECHNIQUE IN THE THEORY OF MODE DIFFRACTION. PART II. CONVERGENCE OF PROJECTION APPROXIMATIONS
Petrusenko I.V., Sirenko Yu.K.
The problem of validity of the truncation procedure for matrix equations of the mode-matching technique is an open question during the all period of applying this technique. The generalized mode-matching technique, which is proposed to solve the problem on mode-diffraction by abrupt discontinuity in the wave guide, yields the Fresnel formulae for matrix operators of mode reflection and transmission instead of the traditional infinite systems of linear algebraic equations. The aim of the present paper is to construct projection approximations for these operator-based Fresnel formulae and to make an analytical study into the qualitative characteristics of their convergence. The theory of operators in the Hilbert space is used. The unconditional strong convergence of finite-dimensional approximations for the operator-based Fresnel formulae to the true scattering operators has been proved analytically. The condition number of matrix approximations has been evaluated. The obtained results allow one to justify rigorously the generalized mode-matching technique which has been developed for effective analysis of microwave devices.
GENERALIZED MODE-MATCHING TECHNIQUE IN THE THEORY OF MODE DIFFRACTION. PART III. RESONANT SCATTERING OF WAVES BY INHOMOGENEITIES
Petrusenko I.V., Sirenko Yu.K.
The problem of correctness of matrix models related to the mode-matching technique for resonant scattering of waves by waveguide discontinuities had remained topical for the whole period of applying this technique. The next open question is the problem of validity of the truncation procedure for these matrix models. The aim of our work is to prove analytically the correctness of the mathematical models in the form of operator-based Fresnel formulae for the mentioned class of mode-diffraction problems, to construct projection approximations for the sought-for scattering operators and to justify their convergence. The generalized mode-matching technique has been used. The «generalized Fresnel formulae for scattering operators» have been derived. The universality of the developed operator model in the form of the Cayley transformation has been established. It has been shown that the correctness of this model is completely determined by the found operator properties of the generalized scattering matrix. The unconditional convergence of the projection approximation to the true solution has been proved analytically. The commonly used mode-matching technique for the scalar mode-diffraction problems is of matrix-operator nature and an adequate mathematical apparatus for this technique is based on the theory of operators in the Hilbert space. The proposed generalization of the mode-matching technique can be useful for rigorous analysis of microwave devices.
AZIMUTAL MODES IN QUASI-OPTICAL DIELECTRIC RESONATOR WITH DIFFRACTION GRATING
Belous O.I., Pazynin V.L., Sukhoruchko O.N., Fisun A.I.
Quasi-optical dielectric resonators are widely used in microwave engineering as the components of source control systems and as well as in the facilities for study of electro-physical properties of substance. The high Q-quality and convenience in service are main positive properties of these resonators. But the frequency intervals between azimuth modes is notably small. The latter circumstance gives a high probability of the frequency jumping. The aim of our investigation is to study theoretically and experimentally a possibility of the spectrum rarefaction of the forced azimuth «whispering gallery» modes of a disk dielectric resonator. There are three resonator types investigated: dielectric resonator without any additional components, dielectric resonator with conducted screen on the cylindrical surface and dielectric resonator with diffraction grating consisting of the conducting strips situated on the lateral cylindrical surface. Computer-aided simulation was carried out by the finite-difference in time-domain (FDTD) method. Experimental study was performed by the standard VSWR-measurer at 8...12 GHz frequency band. By means of computer and full-size experiments there were received the spectra of «whispering gallery» modes of semi disk resonator, resonator covered by screen, and resonator with diffraction grating. The azimuth mode excitation at one frequency with damping of adjacent modes no less than 15...20 dB at the filling coefficient of diffraction grating being equal to q = 0.3 has been derived. FDTD-technique is an adequate grid method for simulation of the forced oscillations in the systems where oscillatory processes are due to both diffraction and the forming of standing waves. Single mode excitation had been accomplished owing to using a diffraction grating in disk resonator.
Veselovska G., Voitovych O., Linkova A., Khlopov G.
ABOUT THE POSSIBILITY OF RADAR «BUREVESTNIK» APPLICATION FOR NAVIGATION IN THE WORLD OCEAN REGIONS WITH INTENSIVE SHIPPING
Dzyuba V.P., Yeryomka V.D., Zykov A.F., Mytsenko I.M., Prokopenko O.I., Roenko A.N., Roskoshniy D.V.
One of the problems in the area of radio wave propagation and radar design is creation of radar facilities for navigation in the regions of the World Ocean with intensive shipping. Ukrainian radioelectronic industry has a large experience in development of different purpose radar systems, one of that is the radar «Burevestnik». This radar is used to control and observe marine surface situation on the naval border check-points of Ukraine. Another possible application of the mentioned radar is its usage for navigation in the World Ocean. The aim of this paper is to estimate and to illustrate the possibility of radar «Burevestnik» effective application for navigation in the World Ocean, to determine radar coverage range statistical distribution functions at different radar cross sections (RCS) of the surface objects and different centimeter radio waves propagation conditions. To solve these problems the centimeter radio waves attenuation factor database created in IRE NASU on the basis of experimental results was used. Radar «Burevestnik» coverage range statistical distribution functions at surface objects RCS s = 100, 1 000, 10 000 m2 and different meteorological conditions in the regions of the World Ocean were determined. Obtained results were compared with that of experimental researches conducted with stationary navigation radars «Don», «Nayada» and «MRL-5». Finally, a conclusion that radar «Burevestnik» designed in Ukraine can be used as a base model for development of new modifications of navigation radars was made.
PREDICTION OF THE REFRACTION COEFFICIENT IN ARBITRARY POINTS OF SPACE USING RESULTS OF MEASUREMENTS OF METEOROLOGICAL PARAMETERS IN BASE STATIONS
Lutsenko V.I., Lutsenko I.V., Sytnik O.V., Ahn N.X., Gudkov V.N.
The systems of global navigation are widely used for detection of objects location. However, disturbances and inhomogeneities of ionosphere and troposphere lead to errors in measurement of objects coordinates. A possible way to decrease errors is taking into account the troposphere influence while processing information in the system of space navigation providing (SSNP). Two main modes of correction introduction are possible: in real time and after session introduction. Both approaches are based on calculation of troposphere delays with the use of meteorological stations data on a sea level. The analysis carried out for Ukraine showed that the order of approximating model practically does not affect measurement error of troposphere delay. The conclusion was drawn on possibility of using model zeroth order, i. e. average data in Ukraine. But for larger countries the use of average data of refraction coefficient values all over the territory will lead to unreasonably great mistakes. That is why the use of standard data of meteorological stations was considered for forecasting troposphere refraction coefficient at the given point of space. The criteria of choosing forecast reference points (similar in terms of behavior of atmosphere refraction coefficients and value of loss function) have been determined. The possibility of using the suggested approach to formation of bases of reference points for forecasting is shown on examples of Ukraine, Russia, Great Britain and China. Correlations for prediction of refraction coefficient values at the given point of space have been obtained. The proposed method could be used in the SSNP of the country while applying troposphere corrections in receivers of the global navigation system.
THE IONOSPHERIC PRECURSOR TO THE 2011 MARCH 11 EARTHQUAKE AS BASED ON THE JAPAN-PACIFIC SUBIONOSPHERIC VLF/LF NETWORK OBSERVATION
Hayakawa M., Hobara Y., Rozhnoi A., Solovieva M., Ohta K., Izutsu J.,
Nakamura T., Yasuda Y., Yamaguchi H., Kasahara Y.
By using the network observation of subionospheric VLF/LF signals in Japan and in Russia, we have found a significant ionospheric perturbation prior to the recent 2011 March 11 Japan earthquake (EQ) in the off-sea of the Tohoku area, which was an exceptionally huge plate-type EQ. A remarkable anomaly (with decrease in the nighttime amplitude and also with enhancement in dispersion) has been detected on March 5 and 6 on the propagation path from the NLK transmitter (Seattle, USA) to Chofu (together with Kochi and Kasugai), and also we have observed the corresponding VLF anomaly during a prolonged period of March 1–6, with minima in the nighttime amplitude on March 3 and 4 on the path from JJI transmitter (Miyazaki, Kyushu) to Kamchatka, Russia.
COHERENT ADDITION OF POWER IN AVALANCHE-GENERATOR DIODES
Lukin K.A., Maksymov P.P.
The basic problem of modern semiconductor microelectronics is the increase of power characteristics of generators and increase of frequency range of their work. Traditionally an increase of power of generators on the basis of avalanche-flights diodes is achieved by addition of power of a few diodes plugged in one resonance contour. In this research an increase of power characteristics is achieved in avalanche-generator diodes in the regime of coherent auto-oscillations. In this regime of an auto-oscillations of electronic and hole constituents of density of useful power take place on one frequency, that provides their coherent addition in the impoverished layer of Si p–n-junction. The calculation of parameters and modeling of work of avalanche-generators diodes in the regime of two-frequency coherent auto-oscillations is executed by the approved a numerical solution methods of equalizations of drift-diffusion model of semiconductors. The power and spectral characteristics of avalanche-generator diodes are calculated. Dependence of frequency, useful power and electronic efficiency on concentration of admixtures and voltage of the reversed bias is studied. Research results are of interest for the developers of power-ful generators of millimetric and submillimetric ranges of wave-lengths.
ABOUT PROSPECTS OF CREATION OF THE SHORT-WAVE PART OF THE MILLIMETER RANGE COAXIAL MAGNETRON
Omirov A.A.
In comparison with other magnetron types coaxial magnetron (CM) possesses the best operational parameters, but its minimum generation wavelength is 8 mm. From references it is known about attempts of the CM creation generating on a wavelength less than 8 mm, however, the developed models parameters turned out to be unsatisfactory. There is no uniform ideology of CM designing in the scientific literature. Available recommendations are intended for cm wavelengths range and comprise errors. It is known about the complexities arising at CM creation in a short-wave part of mm wavelengths range however, there are no recommendations about their overcoming. The technique of mm wavelengths range CM designing, using last scientific researches (for example, application possibility in CM interaction of an electronic stream with the higher spatial harmonic p-mode oscillation) is offered. Ways of overcoming such difficulties arising at CM designing in a short-wave part of the mm wavelengths range, as increase in frequency reorganization density, temperature loading growth on vanes, decrease in a anode slowing down system cylindrical part rigidity are considered. The offered technique clears the way for a short-wave part of the mm wavelengths range CM creation. It is shown that at present CM creation of 4-mm wavelength range is possible.
Chistyakov K.I.
While designing magnetrons of short-wave part of mm wavelengths range, the interaction between electronic stream and lowest spatial harmonic of degenerate oscillations turned out to be the most successful. To eliminate the drawbacks of this interaction the driving inhomogeneities are applied in magnetron resonator system while manufacturing. These inhomogeneities eliminate an intradoublet competition on a working oscillation mode and a competition with doublet components of a high-voltage oscillation type – the competitor. The computational methods of the nonuniform resonator systems given in the literature have the restrictions not allowing making necessary magnetrons design analysis of driving inhomogeneities influence on HF-field structure of the slowing down system. The new computational method stated on the field theory basis and allowing to search all natural frequencies and corresponding HF-field allocations in magnetron slowing down system has been suggested. The calculation example of HF-fields allocation and a spatial harmonics spectrum of magnetron slowing down system of 2 mm wavelengths range with driving inhomogeneities is given. The comparison of driving inhomogeneities in various arrangement combinations is given. The new procedure necessary for nonuniform magnetrons resonator systems in a short-wave part of mm wavelengths range calculation is gained.
Gurko À.A., Chistyakov K.I.
Magnetron is a master microwaves oscillator which is widely used in radiolocation. Decrease in a locator operating wavelength is necessary for increase of its resolving ability and (or) for antennas downsizing. The relative inaccuracy of manufacturing magnetron resonator system increases while advancing in a short-wave part of mm wavelengths range. Manufacturing errors distort the HF-field structure of a working doublet component. This leads to spoilage growth in terms of the efficiency. The indirect estimation of distraction of HF-field spectrum of spatial harmonics in magnetron slowing down system has been suggested. The estimation allows to detect promptly the signs of defects origin in oscillation system of magnetron, which lead to hidden spoilage in terms of the efficiency. The suggested control is realized by means of standard equipment for control of oscillation system at low power, which is used in manufacturing of any magnetron. The initial experiments will allow to get the data necessary for the described control. As a result there will be less spoilage in magnetrons.
Dzubenko M.I., Kolpakov S.N., Popov I.V., Priemko A.A.
The character of scattering surface depends on distribution of diffraction maximums obtained by interaction of diffraction field and a receiver plane. However, the question of forming of the speckle-fields observed as a result of interaction of coherent radiation with the diffusely scattering surfaces described by non-Gaussian distribution of roughness is not enough studied. In this paper the distribution of amplitude of speckle-fields appearing as a result of diffraction of laser radiation on the surfaces after machining is experimentally and theoretically investigated. The mathematical simulation of speckle-field the amplitude distribution of which are not subjected to a Gaussian statistics has been carried out. It is proven that speckle-fields formed as a result of interaction between coherent radiation and rough surfaces are not absolutely random and contain information about the degree of organization that characterizes the object.
Dzubenko M.I., Kornienko Yu.V.
Description of the first laser launch in the IRE NASU, preparation for the Moon location experiment, creation and develop-ment of dye lasers.