Vol 63, No 4 (2018)

Inductive and capacitive isotropic ribbon arrays with a period small compared with the wavelength, placed at the interface between two media, are considered. Boundary value problems for the scattering of plane waves of two polarizations, incident onto the arrays at arbitrary angles, are formulated. The boundary value problems are solved by the Galerkin method. A model of an array is proposed in the form of a semitransparent film on the surfaces of which equivalent boundary conditions relating the fields on both sides of the surfaces are imposed. The theoretical solution is compared with a numerical solutions obtained using a standard system of electromagnetic simulation. It is shown that, in the low-frequency region, the equivalent boundary conditions describe the behavior of the arrays with good accuracy.

Excitation of electromagnetic waves in a two-layer medium by a horizontal antenna or an antenna with flooded electrodes that is situated on the water surface is investigated. The region below the interface between two media is considered. The general solution of the problem is presented in the form of the well studied modified Bessel functions within the framework of a quasi-stationary approximation. In contrast to the scheme, which is widely applied in geoelectricity and connected with the calculation of the field on an interface, the Watson rather than Fok integrals are used. The Watson integrals make it possible to determine the field both on the interface and outside of it. The limit passage is made to the values of the potential and fields, when the interface is approached from below, as well as in the lower conducting medium at the distance equal to the thickness of several skin layers from a source.

An iterative procedure of distribution of power division coefficients in two-channel partial Wilkinson power combiners–dividers forming a multichannel beamforming network (BFN) of antenna arrays (AAs) is proposed. Examples of implementation of 24- and 32-channel BFNs for an AA with cosecant shape of the radiation pattern are presented.

The algorithm characterizing the optimal estimation of the range and its derivatives is examined as applied to a two-position radar system. It is demonstrated that the given algorithm enables us to allow for inhomogeneous compositions of positions and measurement data coming nonsimultaneously from them and stably generate the estimates of the range and its derivatives. Its simulation confirming a high accuracy is implemented.

The issues of color distortion are discussed using the example of a television screen and the current standard television system. The chromaticity distortions between the original and its image on the TV screen obtained with standard color corrector circuits in the camera channel of the TV system are presented. A color correction method substantially suppressing these color distortions in the television receiver is proposed.

The possibility of generation of ultrawideband chaotic oscillation in a frequency band of 10–30 GHz on the basis of the state-of-the-art microelectronic technology has been investigated. Schematic and topological models of a generator of chaotic oscillations based on elements from the 130-nm SiGe technology library have been proposed, developed, and investigated. The dynamics of the oscillation conditions and the energy efficiency of the generator has been analyzed.

A plasma reactor that contains vacuum–arc and magnetron sputtering sources and radio-frequency discharge that generates high-density plasma in the presence of external magnetic field is developed, constructed, and optimized. The reactor can be used for deposition of various functional coatings with ion stimulation. The parameters of the inductive radio-frequency discharge generated in the presence of external magnetic field that serves as a source of assisting ions are optimized. It is shown that the working interval of the induction of external magnetic field corresponds to the resonant excitation of the coupled helicon and Trivelpiece–Gold waves. The effect of magnitude and configuration of magnetic field on the parameters of gas-discharge plasma and ion current in the substrate region is studied in the presence of separately and simultaneously initiated magnetron and inductive discharges. The effect of ion flux that is incident on the films in the course of growth on the structure of functional coatings is analyzed.

The microwave circuit of a parallel-coupled accelerating structure containing accelerating resonators excited by the common high-Q transmission resonator has been investigated. The relations determining the structure operation mode, tuning conditions, and the power supplied to the resonators have been derived.

A setup for the measurement of the stability margin of an immittance AND gate is proposed. The feasibility of the measurement method, which is applicable regardless of whether the gate is stable or potentially unstable, is validated.