Y.K. Sirenko
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Exact 'Absorbing' Conditions in Outer Initial Boundary-Value
Problems of the Electrodynamics of Nonsinusoidal Waves.
Part 2: Waveguide Units and Periodic Structures
In this paper, exact nonlocal radiation conditions are presented for artificial boundaries in the
cross-sections of regular semi-infinite guided-wave structures being the channels (hollow closed waveguides or the Floquet channels)
along which the signal generated by a certain compact resonance unit propagates.
Back
|
L.A. Pazynin
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
A Field of Linear Magnetic Current in a Plane Waveguide with Smoothly
Varying Impedance of Its Walls
The exact Green function of the Helmholtz equation for a gradient impedance junction in a plane waveguide
of fixed cross-section (the impedance analogue of the familiar Epstein transmission layer) is derived with the help
of the theory of the Riemann boundary-value problem. Green's function is given in terms of expansion in two-parameter
family of plane inhomogeneous waves. A number of possible applications are suggested, namely, the transformation ratios
for eigenmodes of the regular part of the waveguide junction segment are derived analytically; the adiabatic
approximation of the theory of smoothly irregular waveguides is estimated; the abnormally high transformation
of the principal zero mode into the first mode is revealed even for an adiabatically smooth impedance junction.
Back
|
N.T. Cherpak, A.A. Barannik, Yu.V. Prokopenko, Yu.F. Filipov, and T.A. Smirnova
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
Frequency Spectrum Evolution of Quasi-Optical Dielectric
Resonators with Conducting Endplates
Resonant frequency evolution of quasi-optical dielectric resonators (QDR) with conducting endplates (CEP) has
been studied experimentally and theoretically under variations of endplate diameter, dielectric disk height and hole-in-disk diameter.
Whispering gallery (WG) modes are excited in the resonators. K-band measurements were carried out using teflon QDR
with aluminum CEP. A large frequency shift has been discovered for HE- and EH-modes at evolution of QDR with CEP
to the open QDR. Moreover, transformation of axial index m=0 into m=1 is observed for HE-mode. In the studied resonators,
HE-modes can only be excited with zero axial indexes. Evolution behavior of WG mode transformation into waveguide
modes is shown as well. The studies allow one to solve a problem of wave mode identification in QDR with CEP.
Back
|
I.V. Korotash*, M. Lorenz**, E.M. Rudenko*, and T.V. Stepanova***
*Institute for Metal Physics, National Academy of Sciences of the Ukraine, Kyiv-03142, Ukraine
**Institute for Experimental Physics II, University of Leipzig, D-04103, Germany
***Physics Technology Institute of Metals and Alloys, Kyiv-03142, Ukraine
Investigation of HTS Microstrip Bandpass Filters for
Extreme Working Conditions
The microstrip bandpass filter based on YBCO thin films for 1.7 GHz with low insertion loss, passband-width about
3 % and high steepness has been developed, manufactured and tested. The technology for an encapsulated housing
of filter, which should be cyclical cooled down to the liquid nitrogen temperature has been developed. The filter has been
designed and manufactured from double-sided YBCO film on sapphire substrate with CeO2 buffer sublayer.
The characteristics of the designed HTS bandpass filter in a housing were stables after 5 cycles of rapid cooling and heating
(300 K ? 77 K 300 K) and more than a year of usage. The degradation of characteristics of the unhermetized filters under
effect of moisture and at a storage in the atmosphere is explored.
Back
|
V.V. Kutuzov, A.E. Kogut, V.A. Solodovnik, and S.N. Kharkovsky
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
On Possibilities of a Spectrum Rarefaction of Forced
Whispering Gallery Modes in Cylindrical Dielectric Resonator
The rarefaction methods of a multimode spectrum of forced whispering gallery modes in a cylindrical
dielectric resonator are investigated experimentally. Possibilities of a rarefaction of the higher-order modes
and a separation of the same kind polarization mode in the investigated resonator are shown. Comparative
analyses of spectral characteristics of modes excited in different ways in resonators based on a dielectric cylinder
are represented.Back
|
Z.D. Kovalyuk, V.P. Makhniy*, and O.I. Yanchuk
Chernivtsi branch of Institute for Materials Science Problems
National Academy of Sciences of Ukraine,
58001, Iryna Vilde St.5 Chernivtsi, Ukraine
*Chernivtsi National University named after Yuri Fedkovich,
58012, Kotsyubinsky St. 2, Chernivtsi, Ukraine
The mechanisms forming photoelectrical properties
of p-GaSe-n-InSe heterojunction
The forming mechanisms of spectral and integral properties p-GaSe-n-InSe photodiodes are investigated versus
their electrophysical parameters of heterojunction components. From our investigation it follows that the photocarriers
are generated in the spatial charge area localized in the less doped heterostructure component. Experimental values of
photocurrent activation energies at the maxima of the photosensitivity spectrum are equal to ~ 1.2 and ~ 1.0 eV, which
correlate well with band gap of materials forming the junction.
Back
|
N.N. Grigorieva*, S.P. Sirenko, V.G. Shakhbazov*, A.I. Fisun,
O.I Belous, N.N. Gorobets*, V.I. Kiyko*, and V.A. Grabina*
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine
12, Academician Proskura St., Kharkov 61085, Ukraine
*V. Karazin National University of Kharkov, 4, Svoboda Sq., Kharkov, 61077, Ukraine
Effect of Linearly and Circularly Polarized Electromagnetic Waves
on Intracellular Electrophoresis of Human Cell Nuclei
The influence of linearly and circularly (right- and left-handed) polarized electromagnetic waves (EMW) of J-, K-, and
L-bands on the electrophoretic mobility of human buccal epithelium cells was studied. The frequency and power flux density
(PFD) dependencies of the radiation efficiency and the effect of the four cell irradiation modes on the index of electronegative
nuclei (ENN) were examined. All the radiation-induced changes of ENN index were compared with the age norm (AN)
defined as the ENN index statistically averaged over the group of relatively healthy people. The experiments have been conducted
with the cells of four female donors of different age (from 21 to 51). The results obtained are indicative of the changes in ENN
index under the influence of electromagnetic radiation (EMR) of EHF and SHF bands, with right-handed polarized waves being more
effective compared to linearly and left-handed polarized waves. The character and magnitude of the ENN changes depend on the index
control value, being independent of the donor's age, EMR frequency and power flux density. The index decrease on irradiation was
commonly observed in the cases where control index value was greater than AN. On the contrary, if the control values are lower than
AN the ENN index increases. The previously obtained data conclusive of the normalizing effect of the low- intensity microwave radiation
on the ENN index are corroborated.
Back
|