卷 61, 编号 4 (2016)

The spectral method for the solution of boundary value electrodynamic problems without the use of the Lorentz calibration is proposed. The method involves autonomous decompositions of the electromagnetic field components, and the Galerkin procedure is applied directly to the Maxwell equations. The efficiency of the method is demonstrated for the example of a rectangular waveguide that is inhomogeneously filled.

It is shown that a new type of the Bragg structure based on pieces of a waveguide-slot line can be created in the microwave band. The amplitude-frequency characteristics of such a structure are described theoretically and investigated experimentally in the frequency range 8–12 GHz. The regularities in the distribution of the electric field intensity in a standing wave appearing in the investigated Bragg structure are established. It is found that a resonance singularity appears in the forbidden zone of the investigated Bragg structure when a defect in the form of the changed length of the central section of a regular waveguide is made.

A formula describing the eikonal distribution on the surface of the main reflector of a doublereflector system of a general form is derived and its expansion in powers of the offset of the source from the focus up to the fourth-order terms is obtained. The analysis and minimization of aberrations for a doublereflector aplanatic Schwarzschild system are performed.

A method for regularized generalized identification is developed for a single stationary finder that works under conditions for significant a priori uncertainty. It is demonstrated that the method involves estimation of parameters in the polynomial model of target motion, coordinates of the final way point (selected from a set of possible points), and approach time for the given point. The applicability conditions are determined for the proposed method. A step-by-step algorithm of the generalized identification of the model of motion for the emitting target is proposed. The numerical experiments on rectiand curvilinear motion of the target are performed.

The problem of processing of signals from fixed land-based radio emission sources (RESs) measured in a monostatic air-borne radio monitoring system is considered. On the basis of the Bayesian approach, an optimal joint procedure for RES identification from radio measurements, estimation of RES state coordinates, and RES type recognition is developed. Relationships obtained in the synthesis of the joint procedure are analyzed. The results of application of the joint procedure are compared with the results obtained by independently synthesized algorithms for RES identification, estimation of RES state coordinates, and RES type recognition.

A words phonetic decoding method in automatic speech recognition is considered. The properties of Kullback–Leibler divergence are used to synthesize the estimation of the distribution of divergence between minimum speech units (e.g., single phonemes) inside a single class. It is demonstrated that the minimum variance of the intraphonemic divergence is reached when the phonetic database is tuned to the voice of a single speaker. The estimations are proven by experimental results on the recognition of vowel sounds and isolated words of Russian language.

Cylindrical and spherical bipolar diodes with divergent electron beams are analyzed. A tendency related to the application of plasma structures in the classical devices of vacuum electronics working in the steady-state and pulsed regimes is discussed.

The results of investigation of a new type of the optical-fiber coherent phase-sensitive reflectometer with two different optical frequencies of probing pulses are presented. The use of pulses with different optical frequencies allows recovering of the signal of an external action on the reflectometer optical fiber by means of phase diversity technique. The applicability of the proposed technique is justified theoretically and experimentally.

The basic design of microwave filters based on surface acoustic waves with a high input power for specialized communication systems and radar and telecommunications equipment is developed.