Begell House Inc.
Telecommunications and Radio Engineering
TRE
0040-2508
74
16
2015
WAVE TRANSMISSION THROUGH A WAVEGUIDE SECTION WITH RANDOMLY CORRUGATED WALLS: A DUAL NATURE OF THE LOCALIZATION
1409-1426
10.1615/TelecomRadEng.v74.i16.10
Yu. V.
Tarasov
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura St., Kharkiv 61085, Ukraine
L.D.
Shostenko
A. Usikov Institute of RadioPhysics and Electronics,National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkiv 61085, Ukraine
multimode waveguide
randomly corrugated boundaries
gradient scattering
wave localization
A theory is developed of wave propagation through waveguide structures which include a finite-length section with randomly corrugated lateral boundaries. It is shown that the principal role in the waveguide state formation is played by the gradient mechanism of scattering where the roughness sharpness is determinative instead of their amplitude. The rough section of the waveguide plays a role of an effective modulated potential barrier whose width coincides with the section length while the height is dependent on the mean sharpness of the waveguide boundary irregularities. Structures of the kind support two types of the wave localization. The first of these consists in a sequential cutoff of the waveguide modes as the irregularity sharpness is increased. This effect results in thinning out the waveguide spectrum such that with sufficiently sharp irregularities the structure operates as an evanescent-mode waveguide. The second mechanism is the conventional Anderson localization associated with multiple scattering of the waveguide modes by random fluctuations of the effective potential. An abrupt increase (up to 100 %) of the waveguide conductance as the waveguide passes to operate in an effectively single-mode regime due to the gradient mode renormalization associated with disappearance in this case of the inter-mode scattering channel.
PROPERTIES OF THE TUNABLE WAVEGUIDE-DIELECTRIC RESONATOR WITH THE INCREASED Q-FACTOR AT THE MILLIMETER-WAVE BAND
1427-1432
10.1615/TelecomRadEng.v74.i16.20
R. I.
Bilous
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proscura St., Kharkov 61085
S. P.
Martynyuk
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
A. P.
Motornenko
A. Usikov Institute of Radio Physics and Electronics National Academy of Sciences of Ukraine
I. G.
Skuratovskiy
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
waveguide-dielectric resonator
evanescent waveguide
eigen frequency and Q-factor
The resonance structures serve as the basis for many electronic devices. Therefore the creation of the effective tunable resonator is the actual and important problem. Using of the waveguide-dielectric resonator insures opportunity for the mechanical frequency tuning over a wide range but at the same time the Q-factor is changed. Recent investigations suggested that the decrease of the unloaded Q-factor of the tuning waveguide-dielectric resonator in the section of the circular cut-off waveguide can be decreased by using the resonance short-circuit plunger calculated on the given frequency. The investigations have been conducted for the 3-cm waveband. This paper is devoted to investigation of the possibility to increase Q-factor of the resonator of the waveguide-dielectric type in the millimeter-wave band where influence of the contact imperfection between the plunger and waveguide walls is essential. As a result of the conducted investigations the Q-factor more than 2 000 within the entire tuning frequency band was obtained for the resonator made of the section of the circuit cut-off waveguide with the Teflon dielectric in the 8-mm waveband.
ELECTRON BUNCHING IN THE KLYNOTRON-TYPE OSCILLATORS. KLYNOTRON AS A FREQUENCY MULTIPLIER
1433-1443
10.1615/TelecomRadEng.v74.i16.30
M. V.
Milcho
A.Ya. Usikov Institute for Radiophysics and Electronics of the National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkiv 61085, Ukraine
vacuum electron device
klynotron
bunching
frequency multiplier
numerical simulation
The easy-to-use and cost-efficient oscillators suitable for the submillimeter waveband and especially in its short-wave part are still a challenge to be solved. Though providing satisfactory results in the long-wave part of the submillimeter waveband, backward wave tubes (BWTs) are as good as inapplicable in its short-wave part. Available engineering methods are not capable of providing extremely thin high-current-density electron beams required for this waveband. Frequency multipliers are able to considerably mitigate such strict requirements to the electron beams. A klynotron-type oscillator can be used for electron beam bunching in the frequency multiplier. In the klynotron oscillator, a wide and comparatively thick sheet electron beam is directed at a small angle to the surface of the slow-wave structure and is partly dissipated on this surface. The output power provided by the klynotron exceeds that of a conventional BWT by several orders. This is a crucial condition for obtaining good (i.e., deep) bunching of an electron beam. Our goal is to investigate the process of dense electron bunching in klynotron-type oscillators and to clarify the conditions of its use for electron beam bunching in a frequency multiplier. In this paper, we analysed the electron bunching in the klynotron numerically, using our proprietary software, specially designed to take into account all specific features of the klynotron operating mode. Three-dimensional motion of electron was investigated in the finite focusing magnetic field. The numeral simulations revealed the effect of "layer-by-layer" bunching of the electron beam in a klynotron-type oscillator. The farther an electron layer is located from the surface of the slow-wave structure, the later electron bunching in that layer occurs. It was shown that by selecting the proper operation mode and the slope angle between of the focusing magnetic field and the comb surface one can obtain dense electron bunches in the part of the beam outside the klynotron slow-wave structure, where the second slow-wave structure should be located functioning as a power take-off. This can be considered as a proof that klynotrons can be used in the frequency multiplier engineering.
PARTICULARITIES OF TRANSFORMATION OF SURFACE ELECTROMAGNETIC WAVES INTO SPATIAL RADIATION WAVES UPON PERIODIC METAL DIELECTRIC STRUCTURES
1445-1456
10.1615/TelecomRadEng.v74.i16.40
G. S.
Vorobyov
Sumy State University, 2, Rymsky-Korsakov St.. Sumy, 244007, Ukraine
A.I.
Ruban
Sumy State University, 2, Rymskogo-Korsakova St., Sumy, 40007, Ukraine
M. V.
Petrovskyi
Sumy State University, 2, Rymskogo-Korsakova St., Sumy, 40007, Ukraine
V.O.
Zhurba
Sumy State University, 2, Rymskogo-Korsakova St., Sumy, 40007, Ukraine
A.A.
Puryga
Sumy State University, 2, Rymskogo-Korsakova St., Sumy, 40007, Ukraine
V.S.
Shubnikov
Sumy State University, 2, Rymskogo-Korsakova St., Sumy, 40007, Ukraine
metal-dielectric structure
the Cherenkov radiation
diffraction radiation
dielectric waveguide
electron beam
Physical processes of transformation of the surface electromagnetic waves from distributed metal-dielectric - electron beam (or dielectric waveguide) structures are theoretically studied and experimentally investigated. The results of theoretical studies are compared with results of experimental investigation related to the above systems and performed within the 4-mm wavelength range. The issues of creation of new devices in the millimeter/submillimeter wavelength ranges with application of metal-dielectric structures are discussed in brief.
STUDY OF THE CHARGE TRANSPORT IN A LOW-TWO-DIMENSIONAL SEMICONDUCTOR STRUCTURE IN VIEW OF THE NON-MARKOV EFFECTS
1457-1466
10.1615/TelecomRadEng.v74.i16.50
S.V.
Grischenko
Kharkov National University of Radio Engineering and Electronics, 14, Lenin Ave, Kharkiv, 61166, Ukraine
O.I.
Sinel'nikova
Kharkov National University of Radio Engineering and Electronics, 14, Lenin Ave, Kharkiv, 61166, Ukraine
S.O.
Yakushev
Kharkov National University of Radio Engineering and Electronics, 14, Lenin Ave, Kharkiv, 61166, Ukraine
V. I.
Fesenko
V. Karazin National University of Kharkov, 4, Svoboda Sq., Kharkiv, 61077; Kharkov National University of Radio Engineering and Electronics, 14, Lenin Ave, Kharkiv, 61166, Ukraine
A. V.
Shulika
Kharkiv National University of Radio Engineering and Electronics, 14, Lenin Ave, Kharkiv, 61166, Ukraine
I. A.
Sukhoivanov
Kharkov National University of Radio Engineering and Electronics, 14, Lenin Ave, Kharkiv, 61166, Ukraine; FIMEE, Universidad de Guanajuato, Salamanca, Mexico
nanostructures
active region
contact
the non-Markov effect
The theoretical study of semiconductor p-i-n structure with a highly doped contact layers have been carried out. In the course of the work it was shown that at a low electron density in the active layer depletion the carrier scattering mechanisms were practically absent. Low electron relaxation time in the contact layers was the main cause of the evolution of states carriers in the active region, thereby increasing the current in the structure and appearance of the connection between the active area and contacts. The dynamic equations for the Fermi-Dirac distribution take into account the non-Markovian character of the electron density distribution in the structure, since they depend on the non-stationary wave vector drift.
OPTICAL PROPERTIES OF MICROPOROUS n-GaAs
1467-1472
10.1615/TelecomRadEng.v74.i16.60
V.P.
Makhnij
Yuri Fedkovych Chernivtsi National University, 2 Kotsyubynsky str., Chernivtsi, 58012, Ukraine
I.I.
German
Yuri Fedkovych Chernivtsi National University, 2 Kotsyubynsky str., Chernivtsi, 58012, Ukraine
V.M.
Sklarchuk
Yuri Fedkovych Chernivtsi National University, 2 Kotsyubynsky str., Chernivtsi, 58012, Ukraine
porous gallium arsenide
size quantization effect
photoluminescence
optical transmission
The (111) oriented n-GaAs substrates were prepared by etching to grow microporous layers. It has been established that the obtained por-GaAs layers are more uniform on the substrate arsenic side B. These layers are similarly oriented pyramids with a base of 2-5 µm consisting of finer nanopyramides having lateral sizes of 1-100 nm. A wide photoluminescence band, observed on the side B in the energy range between 5 eV and 3.2 eV, is owing to the size quantization in the fine nanopyramides. The displacement of a high-energy optical absorption edge in the por-GaAs samples is explained by the joint action of the processes of light scattering on the nanopyramides and volume absorption in the fundamental transition region.
STUDYING THE POSSIBILITY OF LOW- FREQUENCY WHISTLERS GENERATION BY INFRASOUND IN THE LOWER IONOSPHERE DURING THE PERIODS OF POWERFUL ATMOSPHERIC FRONT PASSAGE
1473-1482
10.1615/TelecomRadEng.v74.i16.70
A. M.
Gokov
S. Kuznets Kharkiv National University of Economics, Ministry of Education and Science of Ukraine, 9a, Nauka Ave., Kharkiv 61166, Ukraine; V. Karazin Kharkiv National University, 4, Svobody Sq., Kharkiv 61022, Ukraine
lower ionosphere disturbances
powerful atmospheric front
infrasonic waves
mid-latitude ionospheric D-region
low-frequency whistlers
It is confirmed experimentally that in course of the powerful atmospheric front passage a generation of infrasonic waves with the frequencies f1 ~ 0.4 − 0.8 GHz penetrating up to the heights of the ionospheric E-region (z ~100 −170 km) is possible. Based on the mechanism of the infrasonic waves transformation into the low-frequency whistlers in the ionospheric E-region and the obtained dispersion ratio there were experimentally determined the frequencies of the whistlers f3 ~ 7 − 29 kHz forming a good match with theoretical calculations and data from the reference literature experimental results.
VERTICAL PROFILE OF ATMOSPHERIC CONDUCTIVITY CORRESPONDING TO SCHUMANN RESONANCE PARAMETERS
1483-1495
10.1615/TelecomRadEng.v74.i16.80
A. P.
Nickolaenko
O.Ya. Usikov Institute for Radio Physics and Electronics,
National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkiv 61085, Ukraine
Yu. P.
Galuk
St. Petersburg State University, 35 University Ave., St. Petersburg, Peterhoff,
198504 Russia
Masashi
Hayakawa
Hayakawa Institute of Seismo Electromagnetics Co. Ltd.(Hi-SEM), The University of Electro-Communications (UEC) Alliance Center #521, Advanced & Wireless and Communications Research Center, UEC, Chofu, Tokyo, 182-8585, Japan
vertical profile of atmospheric conductivity
propagation constant of ELF radio waves
power spectra of the Schumann resonance
ELF attenuation of radio waves emitted by ELF transmitters
The search for a realistic vertical conductivity profile of atmosphere remains an update task of great importance for the direct electromagnetic simulations of global electromagnetic (Schumann) resonance. Such a profile is necessary when describing the impact on the ionosphere of the space weather, the pre-seismic activity or other various factors. Knowledge of the regular conductivity profile is of particular importance, since it allows computing of the observed regular parameters of Schumann resonance. Starting from the classic data, we developed the new height conductivity profile of atmosphere in the range from 2 to 98 km. The profile allows obtaining the Schumann resonance parameters consistent with experimental observations. The propagation constant of extremely low frequencies (ELF) radio waves was computed corresponding to this profile by using the rigorous full wave solution. We demonstrate a high correspondence of the frequency dependence obtained to the conventional reference model based on the records of global electromagnetic resonance. The conductivity profiles are also suggested for the ambient day and ambient night conditions. We obtained the propagation constants relevant to these profiles using the full wave solution. The power spectra of Schumann resonance were also computed and compared of the vertical electric field component in the case of uniform global distribution of thunderstorms. Spectra relevant to suggested conductivity profiles were compared with the spectrum obtained in the frameworks of the standard reference model. We also show consistency of the model data obtained with the conductivity profiles with the results of measurements of the radio signals radiated by ELF transmitters.