Vol 20, No 3 (2017)

Questions concerning the use of integral representations of the electromagnetic field for constructing self-sufficient mathematical models of broadband vibrator antennas are considered. The results of the numerical solution of the internal and external problem for some models of broadband vibrators are presented, as well as the results of calculating their input resistance in the frequency band.

We propose the small-size dual-polarized radiator with high isolation. It is intended for use in a phased array with a wide scanning sector. Such radiator can also be used to construct an active phased array for satellite radars with synthesized aperture. The geometrical parameters of the radiator and the four-element module, as well as their general antenna characteristics have been optimized. The optimization results for the main characteristics of the radiator and the four-element module (VSWR, coefficient of isolation, directivity, radiation pattern shape) have been shown in the 6% frequency band, operating in the X-range.

Diffraction problem of electromagnetic wave propagation on system of arbitrary located screens and bodies is considered. Uniqueness and solvability theorems are proved. The problem is reduced to the integro-differential equations in Sobolev spaces. Solvability of system of integro-differential equations is proved also.

The exact solution of parabolic wave equation based on localized in space-time superposition of Gaussian wave beams is discovered in the paper. Some special properties of waveform and its propagation are investigated. A possibility of practical application of focused wave beams and controlling their parameters for obtaining required waveform was considered.

In this paper, we propose a generalized algorithm for hierarchical multi-level modeling of radio-frequency devices of radio-engineering systems, which allows modeling methods to optimize the principle of radio-frequency devices constructing and its microwave components, electrical parameters of radio-frequency devices, technological processes of manufacturing microwave nodes and their elements.

A correspondence is established between the properties of a complex resonance and the singularities of non-self-adjoint self-consistent adjoint boundary-value problems. A phenomenon classified as a «complex resonance» takes place in electrodynamic structures described by non-self-adjoint boundary-value problems. It is shown that in the case of pair excitation of complex waves having complex conjugation in wave numbers and amplitudes, a vibration «attached» to the source is formed, which is described by the adjoint Helmholtz equation, that is, the equation on the right side of which is the solution of the homogeneous boundary value problem. A feature of complex resonance is that it exists in the entire range of complex waves with the obligatory presence of a source.

The main questions for designing the power supply modules and systems are considered. They are the electromagnetic compatibility of power supply modules, the stability of power supply modules and the stability of whole power supply system.

In this paper, we consider the problem of computing color differences between two specified colors in the existing color systems by international Commission on illumination, or as to the accuracy of the color differences obtained by using specific formulas: JPC-79; CMC-based JPC-79 developed by the Committee on colorimetry of the Royal society of dyers and colourists; and the formula recommended in 1994 by international Commission on illumination. At the time, one of the authors (Prof. Lozhkin L.D.) was offered strictly equicontrasting color system, protected by a patent for an invention, but this system was applied to rather complicated mathematical apparatus, based on tensor calculus. This work uses a simple method of calculating color differences, and a fairly simple mathematical apparatus. The results of calculating color differences between two specified colors. This was specially created computer program that allows you to calculate color differences.