2010, volume 15, № 2
the Resonance Excitation Behavior Analysis of Two dimensional screen periodically perforated with circular below cutofF holes
А. О. Perov, А. А. Кirilenko, S. L. Senkevich
4-15
The article considers regularities appeared at the scattering of normally incident electromagnetic wave on the screen having some below-cutoff holes in the periodic cell It is shown that the spacing or element perturbations together with well-known transmission phenomena cause not only the new enhance transmission resonances but the total reflection resonances as well. The explanation of such frequency response behavior is given from spectral theory point of view when the screen is considered as an open resonator, and his lower complex-frequency eigen-oscillations are responsible for the frequency-response forming over the single-mode range. In the context of simple approximated model taking into account a part of eigen-frequency spectrum the main possible peculiarities of frequency response are discussed.
SHAPING OF EXTENDED FIELDS IN THE OPEN RESONATOR WITH TRAPEZOIDAL MIRRORS
V. S. Miroshnichenko, V. G. Dudka, D. V. Yudintsev
16-21
The singularities of use of trapezoidal mirrors for sha-ping extended fields in the open resonator (OR) for therahertz are surveyed. The results of a numerical modeling of properties of resonant modes in two-dimensional OR with trapezoidal mirrors are presented. The Q-factor and field structure for E0q-, E1q- and E2q-modes in OR are determined. The optimization of trapezoidal mirror parameters to obtain a minimum of radiation losses in OR with an extended field is carried out. The singularities of increa-sing fields shaping in OR at rotation displacement of one trapezoidal mirror are surveyed. The comparison of mode properties in OR with corner mirrors and trapezoidal mirrors is carried out.
ROTARY JOINT FOR EHF BAND
A. P. Yevdokymov, V. V. Kryzhanovskiy, V. L. Pazynin, K. Yu. Sirenko
22-26
Rotary joint for EHF band is designed for central frequency 33 GHz. Main structure is optimized, consisting of two flanges mounted with a spacing, one having circular isolating grooves. Programs for electromagnetic simulation were used, realizing the strict time-domain approaches, based on standard finite difference approximation of the modeling initial boundary value problem. Three isolating grooves provide large spacing between flanges. Two models of rotary joint were manufactured and investigated, typical loss value being 0,4–0,8 dB within 1,5 GHz band.
EXCITATION SYSTEM OF A DISK DIELECTRIC RESONATOR IN THE CRYODIELECTROMETER
R. V. Golovashchenko
27-31
The description of the design of the resonance unit for the millimeter waveband cryodielectrometer on the base of a disk dielectric resonator working on whispering gallery modes is presented and main characteristics of the unit are investigated.
ANALYSIS OF LINE-FED CYLINDRICAL MICROSTRIP ANTENNAS WITH PATCHES OF AN ARBITRARY SHAPE
А. Ye. Svezhentsev
32-41
The goal of this paper is the development of the effective approach to the analysis of the line-fed cylindrical microstrip antennas with patches of arbitrary shapes. This approach is based on the moment method solution in the spectral domain. The key point under consideration was to enhance the computation efficiency of mutual impedance matrix elements by subtracting an asymptotical behavior of the spectral Green’s function. Before the main terms of such asymptotical behavior have been heuristically obtained using the solution for the planar case. In this paper the asymptotical behavior has been discussed rigorously for cylindrical geometry and additional terms have been derived. The input impedance has been calculated for different patch geometry. The comparison with the experimental data has been given.
SOUTH AMERICAN THUNDERSTORMS AND THE SOUTH ATLANTIC GEOMAGNETIC ANOMALY
O. В. Pechony, A. Р. Nickolaenko
42-51
Extensive information on global lightning activity was accumulated by the spaceborvne Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS), which is applied in different research. Precipitation of cosmic particles from Earth’s radiation belts causes numerous false lightning detections when satellites pass through the South Atlantic Anomaly (SAA), centered near the lower east coast of South America. Aggressive filtering procedures were applied toward the data resulting in inavoidable losses of true flashes along with radiation noise. Differences in exposure to SAA and filtering procedures result in notable differences between OTD and LIS lightning distributions in this region. We compare optical data with DEMETER satillite observations and discuss possible causes of deviations among OTD and LIS data We also suggest that high lightning activity in the SAA region indicated by LIS might be a manifestation of a link between the space and treestrial weather, and, possibly, a yet unexplored feedback mechanism between lightning discharges and cosmic particle precipitation.
WAVEFORMS OF NATURAL ELF RADIO SIGNALS
A. P. Nickolaenko
52-62
We analyze waveforms of natural ELF transient events. It is shown that model waveforms are observed with the wide band receiver at places with an unusually low level of industrial interference. In conclusion we describe the extracting of natural ELF transient signal from under the industrial noise by using the singular spectral analysis.
A technique for lightning location and estimation of the lower ionosphere parameters using tweek-atmospherics
A. V. Shvets, Yu. V. Gorishnya
63-70
A technique for distance finding to the source of pulse radiation (lightning discharge) and the height of the Earth-ionosphere waveguide is described. The technique is based on the phenomenon of interference between waveguide modes in spectra of tweek-atmosferics (tweeks), which are observed at night. Using the proposed technique we have defined distances to sources (in the range from 500 to 4 000 km) for an ensemble of experimental records, performed in the Atlantic and Indian oceans. The obtained from the analysis the ionosphere height variations were 5–6 km overnight and 2–3 km on the seasonal time scale.
The INFLUENCE OF WATER AND WATER-acid aerosol on the energy balance OF troposphere during solar-proton events
А. L. Kovorotniy, Yu. V. Goncharenko, V. N. Gorobets
71-76
The article is considers the influence of water and water-acid aerosol layers on the energy balance of the Earth atmosphere during solar proton events at the high latitudes.
During solar flares, shown that flow of solar energy reached the Earth's surface, may decrease at 6–11 % at the expense of reflection from the aerosol layer, which generate consequently the ionizing effects of high-energy solar protons.
SCATTERING OF ELECTRONS ON PLASMA OSCILLATIONS IN THE STRUCTURE OF SEMICONDUCTOR-DIELECTRIC-SEMICONCUCTOR
N. N. Beletskii, S. I. Khankina, V. M. Yakovenko, I. V. Yakovenko
77-82
The interaction of an electron with plasmons in the structure semiconductor-dielectric-semiconductor is investigated. The probabilities of radiation and absorption of plasmons by the electron which passes through the boundary of media taking into account the influence of the potential barrier are found.
The conditions when processes of emission prevail over processes of absorption are obtained.
GIANT MAGNETORESISTANCE OF TWO-BARRIER MAGNETIC TUNNEL JUNCTIONS
N. N. Beletskii, S. A. Borysenko
83-86
Giant magnetoresistance of two-barrier magnetic tunnel junctions (TMTJ) has been investigated theoretically. The TMTJ are investigated within the spin-polarized two-zone model of free electrons in ferromagnetic electrodes (FE). It is shown that the tunnel magnetoresistance of the DTMJ can reach 100 %.
GRAZING INCIDENCE REFLECTIVITY OF HIGH-Tc SUPERCONDUCTORS:
MM WAVE TECHNIQUE OF CONDUCTIVITY MEASUREMENTS
A. I. Gubin, N. T. Cherpak, A. A. Lavrinovich
87-91
Non-resonant nondestructive technique has been described for investigation of high-temperature superconductive and relative materials through the measurement of the microwave reflection at grazing incidence. As authors discussed earlier, a reflection coefficient of the electromagnetic wave at grazing incidence can be used to determine an absolute complex conductivity over a wide temperature and frequency range. As of now the experimental measurement setup was realized in millimeter wave range using waveguide phase bridge based approach. The conductivity of YBa2Cu3O7-d film was measured at temperatures higher than critical.
Mode interaction in a slow wave resonator with electron beam
K. A. Lukin, E. M. Khutoryan
92-101
The excitation of slow wave resonator that is an electrodynamic structure for resonance backward wave oscillator and clinotron by electron beam has been considered. Analysis of electrons interaction with resonator field has been carried out provided mode competition.
DYNAMICS OF INTENSIVE ELETRON BEAM IN DISK-LOADED WAVEGUIDE WITH VARIABLE PHASE VELOCITY
V. F. Zhiglo, A. I. Zykov, V. S. Kovalenko, K. Yu. Kramarenko, V. А. Kushnir, V. V. Mytrochenko, А. N. Opanasenko
102-108
Results of numerical simulation of electron dynamics in an unhomogeneous disk-loaded waveguide which is used in the S-band linac with average power of an accelerated beam of 10 kW are presented. Two approaches taking into account the self-fields of beam radiation are considered: the first method estimative based on the power diffusion equation; the second onebased on of self-consistent equations of field excitation and particles motion. The self-consistent approach showed the presence of substantial phase slipping of particles in the homogeneous part of the rf structure, conditioned by the reactive beam loading.
NEGATIVE DIFFERENTIAL CONDUCTIVITY SEMICONDACTORS DIODE WITH TUNNEL SIDE BORDERS
E. D. Prokhorov, O. V. Botsula
109-113
The diode that have negative differential conductivity (NDC) due to tunneling or resonance tunnel electron through lateral facet of the diode is considered. This diodes cab be used for generation, amplifier and frequency multiplication. The arising condition of NDC, current and current-voltage characteristics have been determined. The planar and type of “sandwich” diode structures are conceded.