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Vol 70, No 11 (2025)
ELECTRODYNAMICS AND RADIO WAVE PROPAGATION
Radiation pattern of electric and magnetic currents located near a smooth convex conductive surface of large electrical size
Abstract
Using the parabolic equation method, approximate asymptotic expressions are obtained for the radiation patterns of electric and magnetic dipoles located near a smooth, convex conducting surface of large electrical size. These expressions are expressed in terms of the Fock function in the light, penumbra, and shadow regions relative to the field source. In the penumbra and shadow regions, they supplement known solutions based on the parabolic equation method with the following asymptotic term, which takes into account the torsion of geodesic lines (surface rays). It is shown that for surface sources, the obtained expressions agree with the corresponding expressions based on the uniform geometric theory of diffraction. The radiation patterns of arbitrary sources are found by integrating the products of the dipole radiation patterns with the current density over the source coordinates. General expressions are specified for resonant “half-wave” radiators: slots on the surface and vibrators elevated above the surface, as well as for conducting spheres and a circular cone. The numerical results for calculating the radiation patterns of half-wave slots and dipoles on a sphere, cylinder, and cone are in good agreement with the results of calculations by other authors and with calculations using the rigorous eigenfunction method. A simplified version of the formulas is proposed that does not require constructing geodesic lines on the surface and is suitable for calculating the radiation pattern in the light and penumbra regions.
1005-1020
Waveguide 180 degree turns
Abstract
1021-1031
Electromagnetic simulation of the antenna array with two-dimensional frequency scanning
Abstract
1032-1048
Antenna feeder devices
Design and experimental investigation of a multi-beam antenna irradiator for n79 range
Abstract
1049-1066
Antenna array with element sector type radiation pattern
Abstract
1067-1075
THEORY AND METHODS OF SIGNAL PROCESSING
About new methods and algorithms for processing data from radiophysical environmental monitoring
Abstract
The paper examines new methods and algorithms for processing radiophysical monitoring data during detection and classification of anomalous phenomena on the water surface. The functions of the monitoring system fixator are analyzed in detail. The feasibility estimates of the fixator unit are obtained. Mathematical models of “spotting” of background characteristics of the studied space are developed. The modular structure of the statistical modeling system for spotting is shown. Specific examples of classification of phenomena on the water surface using radiophysical data from the Kosmos-1500 satellite are given. In addition, statistical characteristics of the “spotting” of brightness temperatures obtained for the most informative thresholds for the Pacific regions are analyzed.
1076-1086
Windows with low energy losses for observing the spectrum of a weak signal against a background of frequency-shifted powerful interference
Abstract
Windows with low energy losses are considered which intended for observing the spectrum of a weak signal against a background of powerful frequency-shifted interference. A method for the synthesis of windows with low energy losses is proposed. The method provides the simplest way of calculation of window samples and minimum level of maximum spectral sidelobe at the specified parameters of the application. A representative number of synthesized windows is presented, tables of their parameters are given, and window characteristics are analyzed.
1087-1094
Identification of signals under statistical uncertainty
Abstract
1095-1101
The algorithm for the formation of non-binary cascaded Gordon–Mills–Welch sequences
Abstract
1102-1108
ТЕОРИЯ РАДИОТЕХНИЧЕСКИХ ЦЕПЕЙ
Obtaining analytical expressions for the characteristics of field-effect transistors using a special Lambert function
Abstract
1109-1114
ЭЛЕКТРОННАЯ И ИОННАЯ ОПТИКА
To mode of the most nearness to ideal magnetic orientation for dense electron beams
Abstract
1115-1122
PHYSICAL PROCESSES IN ELECTRONIC DEVICES
Suppressionof the contribution ofintraband absorptionto the characteristic relaxation time ofthe narrowly directed partof stimulated picosecond emissionof the AlxGa1–xAs–GaAs–AlxGa1–xAs heterostructure
Abstract
It has been experimentally found that the return to the active region of the part of its own intense stimulated picosecond emission reflected from the end face of theAlxGa1–xAs–GaAs–AlxGa1–xAs heterostructure leads to a significant reduction in the characteristic relaxation time of the narrowly directed portion of the generated emission. The reduction occurs due to the controlled reduction, upto the disappearance, of the contribution to the characteristic time created by the absorption of emission by free charge carriers.
1123-1132