Begell House Inc.
Telecommunications and Radio Engineering
TRE
0040-2508
73
7
2014
THE VAVILOV-CHERENKOV RESONANCE RADIATION IN DISPERSIVE METAMATERIALS
569-586
10.1615/TelecomRadEng.v73.i7.10
P. N.
Melezhik
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085, Ukraine
A. Ye.
Poyedinchuk
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura St., Kharkov 61085, Ukraine
N. P.
Yashina
O.Ya. Usikov Institute for Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkiv 61085, Ukraine
G.
Granet
Institut Pascal, Universite Blaise-Pascal, Clermont-Ferrand, France
metamaterial
periodic interface
the Vavilov-Cherenkov resonance radiation
dispersion relation for the constitutive parameters
synchronism
charge-particle flow
The Vavilov-Cherenkov effect is investigated with respect to a beam of charged particles moving over a surface (generally periodic) of a dispersive medium. Depending on the frequency range, the medium can be right-handed (usual dielectric), mono-negative (either permittivity or permeability is negative) or left-handed (the permittivity and permeability are both negative). The presented results have been obtained using rigorous mathematical models and appropriate effective computational algorithms. The study is focused at qualitatively new resonance effects arising as a result of combining micro- and macro-periodic structures in the electromagnetic problem under consideration. These are a micro- (or even nano) periodic structure of the metamaterial and macro-period of the diffraction grating which is comparable with the wavelength of the electron beam-produced radiation.
RIGOROUS SOLUTION OF COMPLEX 2D PROBLEMS OF RADIATION AND PROPAGATION OF IMPULSE AND MONOCHROMATIC ELECTROMAGNETIC WAVES
587-603
10.1615/TelecomRadEng.v73.i7.20
D.M.
Davletbayeva
L.N. Gumilyov Eurasian National University 5, Kazhimukan St., Astana 010008, Republic of Kazakhstan
Zh.K.
Kabytay
L.N. Gumilyov Eurasian National University 5, Kazhimukan St., Astana 010008, Republic of Kazakhstan
Yuriy
Sirenko
IRE NAN Ukraine
electromagnetic waves
radiation and propagation
initial boundary-value problems
exact absorbing conditions
In the paper, some models are analyzed which allow solving rather complex 2D problems of the electromagnetic wave radiation and propagation with a required accuracy using ordinary personal computers. The problems are of great importance for the theory and practical applications. The basis for constructing models of the kind are the exact absorbing conditions which use makes it possible to reduce the original open initial boundary-value problems to equivalent closed problems, i.e., to such problems which can be solved numerically using the standard net methods.
RELAY-RACE INTERACTION IN MICROWAVE DEVICES
605-620
10.1615/TelecomRadEng.v73.i7.30
G. A.
Alexeev
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
L. V.
Stulova
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura St., Kharkov 61085, Ukraine
"radio light-spot"
short-term interaction between electrons and a spatial harmonic field
coherent collective interaction between electron bunch and a microwave field
The survey deals with analysis of some specific features of a collective interaction between distributed electron bunches, passing through a spatially concentrated layer of a microwave field, while individual electrons are momentarily interacting with the transverse component of the traveling spatial harmonic of field. It was revealed that, due to the synchronism between the movement of the short-term interaction area and the harmonic's phase velocity, the coherent collective interaction efficiency is maximum. In terms of quality, this mode corresponds to a relay-race interaction between an electron bunch and a traveling harmonic of a microwave field. The incentives to this study were provided by the impelling demand in new interaction mechanisms and new structural solutions for SHF-oscillators. We substantiate the feasibility of developing devices with the collective relay-race interaction between distributed electron bunches and a traveling wave of an electrodynamic structure, characterized by an increased output power.
EXPERIMENTAL INVESTIGATION OF KLYNOTRON EFFECTS IN THE DIFFRACTION RADIATION OSCILLATOR
621-628
10.1615/TelecomRadEng.v73.i7.40
M. Yu.
Demchenko
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine. 12, Academician Proskura St., Kharkov 61085, Ukraine
V. G.
Kurin
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura Str., Kharkiv 61085, Ukraine
Ye. B.
Senkevich
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura St., Kharkov 61085, Ukraine
Smith-Purcell radiation
diffraction radiation oscillators
klynotron
accompanying klynotron effects
deflection electrode
dispersing bevels
Nowadays there is no viable alternative for vacuum sources of continuous radiation in the THz range either of semiconductor lasers due to their low power (10−6 W), or among the lasers, which operate only at discrete frequencies. Among the existing vacuum sources of O-type the diffraction radiation oscillators (DRO) stand out for high frequency stability, narrow spectrum of the output signal, low noise and a wide range of electromechanical tuning and a relatively high level of output power. However, under the advancement in the THz range there is a problem of DRO efficiency increasing, that is connected with the need to ensure a high intensity of the high-frequency (HF) field in the region of electron-wave interaction. The use of klynotron effect is one of the ways to solve the problem. The using of klynotron effects to enhance the interaction efficiency of the electron beam with a HF field in the DRO is discussed in this paper. Experimental study of the klynotron effect carried out in the DRO with additional (deflection) electrode, as well as in DRO, when the electron beam is entered into the interaction space through dispersing bevels. It is shown that klynotron effects, the existence of which is due to non-removable fluctuations of the electron beam, accompany the interaction of the electron beam with the HF field. Increasing the electron beam utilization factor it is possible to reduce the starting current of the DRO, as well as, to obtain a higher generation power at low values of the magnetic focusing field.
SUPPRESSION OF THE SLOT WAVE MODE IN COAXIAL MAGNETRONS OF MILLIMETER WAVE BAND
629-638
10.1615/TelecomRadEng.v73.i7.50
A. A.
Omirov
OJSC "Vladykinskiy Mechanical Plant" 58, Dmitrovskoe highway, Moscow, 127238, Russia
coaxial magnetron
millimeter wave band
slot wave mode
reactive "destruction" of the spatial harmonics' spectrum of a HF-field
Among all competing oscillation modes in a coaxial magnetron (CM) the slot wave mode is the most challenging to deal with. Effective reactive suppression of this mode allows to increase magnetron's efficiency as the dissipative suppression releases. The reported in the scientific papers methods of calculating the slot wave mode parameters are not free of errors and inappropriate for the case when the peripheral wall of the anode slowing system (ASS) is thicker than 0.1λ. There are either no research data on the reactive suppression of the slot wave mode in a CM of millimeter (mm) wave band. The errors found in the existing method of slow wave mode parameter calculation were eliminated. Some modification of the calculation algorithm was suggested, as well as a new method, applicable to ASS with a peripheral wall thicker than 0.1λ. The suggested method was developed to reactively suppress slow oscillation mode in a CM of mm wave band by means of rectangular coupling slots of various axial length. A close attention is given to the process of "destruction: of spatial harmonics spectrum and of the HF-field structure of the slot wave mode under the influence of the reactive suppression. The research results allow to make a conclusion that a reactive "destruction" of the slot wave mode in a CM of mm wave band can be achieved by grouping the rectangular coupling slots of various axial length, while the suppression would be at least as efficient as in the centimeter (cm) wave band, where the coupling slots profiles are diverse. The results obtained in this research increase our knowledge about the methods of the reactive suppression of slot wave modes in a CM, and can be useful in the development and improvement of CM parameters both in the centimeter and millimeter wave band.
SPECTRAL CHARACTERISTICS OF MUSCULAR CONTRACTIONS: SIMULATION AND EXPERIMENT
639-646
10.1615/TelecomRadEng.v73.i7.60
O.S.
Matchenko
V. Karazin National University of Kharkiv, 4, Svoboda Sq., Kharkiv, 61077, Ukraine
I.V.
Skresanova
V. Karazin National University of Kharkiv, 4, Svoboda Sq., Kharkiv, 61077, Ukraine
D.A.
Tolstoluzhskiy
V. Karazin National University of Kharkiv, 4, Svoboda Sq., Kharkiv, 61077, Ukraine
E.A.
Barannik
V. Karazin National University of Kharkiv, 4, Svoboda Sq., Kharkiv, 61077, Ukraine
the Doppler ultrasound myography
muscle contraction
computer simulation
The present article deals with the computer simulation of the processes of correlated and uncorrelated muscular contractions. Simple physical model underlies the computer program which can be used for the real-time analysis of an experimental data obtained by means of the ultrasound Doppler myography. The experimental spectra of muscular contractions were compared with those simulated. The consistency among the results promises for the wide practical applying of the developed approaches and methods.
IMPROVING THE RELIABILITY OF RHINOMANOMETRY DIAGNOSTICS BY CONSIDERING STATISTICAL CHARACTERISTICS OF MEASURED SIGNALS
647-655
10.1615/TelecomRadEng.v73.i7.70
O. G.
Avrunin
Kharkiv National University of Radio Electronics, 14 Nauka Ave, Kharkiv 61166, Ukraine
rhinomanometry
medical equipment
respiratory characteristics
statistics
Current paper describes the technique of automated analysis based on the rhinomanometric diagnostics, as well as the possible ways to improve the reliability of measuring technique by optimization of algorithmic model to express-monitoring of nasal breathing. Our results have shown the applicability of suggested techniques − variance and piecewise regression transformations of dynamic signals − to obtain additional informative parameters under the time limit biological observation. It has been practically revealed that space dimension of informative parameters affects on the error probability of diagnostics. The value of proposed technique is that it permits to study the influence of individual characteristics of the patient's breathing on rhinomanometry results, and to improve automated diagnosis during respiratory testing.