Radio physics and electronics

15-20

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

We have studied the possibility of designing compact polarization plane rotator electromagnetic waves on the basis of the structures with dihedral symmetry, and formed by 5-resonant slotted apertures with rectangular irises. The proposed structure allows to rotate polarization plane at angles being different from 90° and have an acceptable matching in a given frequency band.

27-37

Authors: I. G. Kudintseva, S. A. Nikolayenko, A. P. Nickolaenko, M. Hayakawa

Simulation of signals of the global electromagnetic reso-nance is of great interest in theory and the measurement practice. We describe a method of generating the artificial Schumann resonance signal and present its major features. It is shown that the synthesized time domain record exhibits many of the experimentally observed characteristics pertinent to the natural radio signals. We propose using the synthetic signals in simulations of natural ELF radio noise and in calibrations of the receiving equipment.

45-50

Authors: А.А. Barannik, S.А. Vitusevich, I.А. Protsenko

WGM resonators can be used for studies of condensed matter, especially for the study of the dielectric liquids properties. However, the electromagnetic properties of the real resonator structures are not well understood. The microwave response of quasioptical radially-two-layered dielectric resonator in the form of a cylindrical ring sandwiched between two flat conducting endplates is studied. Usually real resonator has an additional layer between the leucosapphire ring and a conducting surface, that eliminates a possibility of the rigorous solution for the corresponding electromagnetic problem. The leucosapphire resonator is studied with numerical modeling methods and experimental measurements in the Ka-band. A good agreement between the experimentally measured and calculated values of frequencies and Q-factors is achieved. It is shown that the resonator allows the measurement of the complex permittivity of solutions with an error of about 3 %.

57-67

Authors: V. V. Ovsyanikov

The results of studies in the range of microwave radio characteristics of linear wire electrically small antennas, which important properties are small size and weight, are presented. In the studies theoretical approximate, rigorous, and experimental methods are applied. The calculations are performed by approximate and rigorous integral equation using modern computer software environments super NEC, FEKO and others. For the first time we propose the method of structural-parametric optimization and approximate analysis of antennas with included lumped inductive and capacitive loads in the emitting branches. Approximate formulas for determining the value include curved pin and loop antenna reactive loads and formulas to determine their input impedances. According to these formulas, we perform the calculations of the values of inductive and capacitive loads, which are confirmed experimentally. The results of theoretical and experimental studies of Q-factor and efficiency of pin, spiral and loop electrically small antennas with reactive loads included in their branches are presented for the first time. The results show that when reducing the electric size of arm of pin bent antennas to values of 0.01 to 0.03 with respect to the operating wavelength of conventional antennas arm size, the efficiencies of antennas are reduced to 20 % or less for values of Q-factor losses in the range of 130 to 1 000. From the efficiency measuring results it follows that shortening the electrical length of investigated antennas by half, relative to the usual size, both with included inductive load, and as a cylindrical helix, reduces the efficiency of these antennas from 100 % to 75…85 % as compared with conventional pin antennas. Shortening the electrical length reduces the efficiency of the antenna three times up to 40…50 %. Obviously further shortening leads to further reduction of antennas efficiency. The material contained in the article may be useful for research and development of electrically small and miniature antennas in microstrip and other performance.

77-85

Authors: K. A. Lukin, D. N. Tatyanko, A. B. Pikh, O. V. Zemlyaniy

The results of applying the method of spectral interferometry in optical band for measuring the thicknesses of thin films are presented in this paper. We have analyzed analytically and experimentally the spectrum of the total radiation at the output of the fiber optic Fabry-Perot interferometer which is formed by broadband light reflections from the multilayer structures, including the special case of two reflections when the object of study are the thin films. The spectrum informative components corresponding to the distances to the reflective surfaces have been obtained. The results of experiments conducted using broadband LED light sources of optical radiation are in full agreement with the results which were obtained theoretically. A software tool with a graphical user interface for processing and visualization of the experimental results has been developed. The obtained results will help improve the performance of the measuring equipment in medicine, profilometry, and create standards for metrology.