Radio physics and electronics

11-19

Authors: A. A. Kirilenko, D. Yu. Kulik, S. A. Steshenko

While designing waveguide junctions, one of the actual tasks is the development of a mode-matching technique for calculating heterogeneities given in different coordinate systems. This paper presents the method for calculating multiport junction using the fields coupling in radial and rectangular waveguides. We proposed a modification of this method for junctions with several shorted ports. The accuracy and convergence of this method were researched.

30-39

Authors: Ye. I. Yatsevich, A. P. Nickolaenko, A. V. Shvets, A. V. Koloskov, O. V. Budanov

Organization of continuous observations of Schumann resonance (SR) opens up the possibility of permanent monitoring the lower ionosphere and global storms. The existing methods for monitoring thunderstorm activity with SR are developed in detail only for point sources. However, the current models of radiation sources are too simplistic. In this connection, the development of semi-empirical source models, in which the intensity distribution is determined by the data from satellite observations of global storms, becomes very important. The paper compares the long-term experimental SR data accumulated in the Ukrainian Antarctic Station “Akademik Vernadsky” with the results of calculations of SR in the two-component OTD-model. It is shown that the model, despite the detailed distribution of lightning sources according to optical observations from space, is consistent with the experiment only partially. On the daily time scale, the two-component OTD-model quite well reflects the position of the main maximum of the global storms and their intensity, but the position of individual sources is described not precisely enough for an adequate representation of the diurnal variations in peak frequencies. The model describes quite well the annual and interannual variations in peak frequency of the magnetic components Hy. It is shown that the inter-annual variations of peak frequencies can be attributed to a change in height of the ionosphere and drift sources from year to year, and the long-term drift of the peak frequency is associated with the modification of the ionosphere during solar cycle.

49-55

Authors: A. V. Shvets, A. P. Kryvonos, V. K. Ivanov

The task of measurements of the narrowband signals emitted by navigation and communication radios and broadband signals – radiation lightning arises in studies of the lower ionosphere by radio occultation of the Earth-ionosphere waveguide by low-frequency radio waves. Creating a universal receiver set for synchronous measurements of natural and artificial signals is of interest for increasing the information content of the data. The article discusses how to optimize the parameters of magnetic and electric field sensors to provide required bandwidth, dynamic range and matching with the input circuits of antenna amplifiers for noises. We present the algorithms for calculating the design parameters of the field sensors and a description of the pro-program-hardware complex for measurement of pulse and narrow band electromagnetic fields in the ELF and VLF ranges. The software part of the complex, implemented on a personal computer, allows estimating the absolute level, spectral composition, and polarization characteristics of the recorded pulse and narrowband fields in real time and storing the data around the clock.

60-67

Authors: I. M. Mytsenko, D. D. Khalameyda

Features of construction of mm-band and cm-band radiometers based on satellite low noise blocks (SLNB) are examined. The characteristics of the developed and constructed radiometer layout are presented. The experimental results are shown and compared with the published data. The possibility of using SLNB as an HF intermediate amplifier of mm-band radiometers and two-bandwidth radiometers is examined. A conclusion about receiving apparatus has been made.

77-82

Authors: S. S. Apostolov, D. A. Iakushev, N. M. Makarov, A. A. Shmat’ko, V. A. Yampol’skii

We theoretically study eigenstates of electromagnetic field inside a one-dimensional photonic crystal containing a defect slab of layered superconductor. Basing on the transfer matrix formalism along with the electrodynamics of Josephson plasma, we obtain the dispersion relations describing the THz electromagnetic modes localized on defect. We consider both symmetric and antisymmetric configuration of defect in photonic crystal. The comparison of the dispersion spectra of the localized states for the layered-superconducting defect and the pure insulating defect reveals the features of the studied system.