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Vol 69, No 4 (2024)

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ЭЛЕКТРОДИНАМИКА И РАСПРОСТРАНЕНИЕ РАДИОВОЛН

The proposed mechanism of glow of mesosphere clouds

Bordonskiy G.S., Gurulev A.A., Orlov A.O., Kazantsev V.A.

Abstract

The question of the physical mechanism of electromagnetic radiation scattering by mesospheric (noctilucent) clouds is considered. A hypothesis has been expressed about the special electromagnetic characteristics of nanometer-sized ice particles that make up mesospheric clouds. Particle ice consists of a recently discovered crystalline modification of water — ice 0, formed by the condensation of vapor on dust particles at temperatures of –140…–23°C. Ice 0 is a ferroelectric, and upon contact with a dielectric, a layer with high electrical conductivity is formed. Due to plasmon resonance in nanosized layers, strong scattering of electromagnetic radiation occurs over a wide frequency range. This mechanism causes the glow of noctilucent clouds when illuminated by the radiation of the Sun.

Radiotehnika i èlektronika. 2024;69(4):307-315
pages 307-315 views

Dispersion of dielectric permittivity for composite material based on resistive dipoles

Ponomarenko V.I., Lagunov I.M.

Abstract

A correspondence has been established between the electrodynamic characteristics of a thin conductive cylindrical dipole and a needle-shaped ellipsoid. A well-known experimental result is theoretically justified, according to which an ellipsoid of the same material inscribed in it corresponds to a dipole. It is shown that, depending on the magnitude of the skin effect, the dispersion dependence of the effective dielectric constant of a dipole-based composite can correspond to both the Lorentz dielectric model and the Debye model. The results of calculating the dielectric constant of the composite according to various mixing formulas are compared with experimental data.

Radiotehnika i èlektronika. 2024;69(4):316-321
pages 316-321 views

СТАТИСТИЧЕСКАЯ ФИЗИКА

Statistical analysis of the matrix method for measuring the radar characteristics of objects

Ponkin V.A., Kiryanov O.E., Korda N.S.

Abstract

The matrix method for measuring the radar characteristics of objects is examined. The method involves irradiating the object with a system of independent test fields, receiving the set of scattered fields, and performing posterior processing of the obtained results based on the superposition principle to determine the required radar characteristics of the object. An analysis of the information capabilities of the matrix method for measuring linear and nonlinear radar characteristics of objects is conducted, considering random errors in the registration of the amplitude and phase of the test signals. The variances of the desired linear and nonlinear radar characteristics of objects are determined, assuming a high signal-to-noise ratio in each test signal reception channel and maximum likelihood estimation of the amplitude and phase of the test signals. It is established that the matrix method for measuring radar characteristics of objects is functional under real conditions involving noise and interference.

Radiotehnika i èlektronika. 2024;69(4):322-327
pages 322-327 views

ТЕОРИЯ И МЕТОДЫ ОБРАБОТКИ СИГНАЛОВ

Potential characteristics of direction finder with interference compensator and a direction finder with an adaptive antenna array with limitations in the event of interference in the main lobe of the antenna pattern

Kalenov E.N.

Abstract

The displacement of the bearing estimate in a direction finder with an adaptive noise compensator, its sensitivity and the sensitivity of a direction finder with an adaptive antenna array with restrictions have been studied depending on the antenna radiation pattern, the angular position of the signal and local interference, the correlation of distributed noise and spectral densities of signal power, noise and interference. A comparative analysis of the accuracy and sensitivity of these direction finders in the event of interference in the main lobe of the antenna pattern was carried out for a linear equidistant antenna array.

Radiotehnika i èlektronika. 2024;69(4):328-338
pages 328-338 views

Linear prediction coefficients correction method for digital speech processing systems with data compression based on the autoregressive model of a voice signal

Savchenko V.V., Savchenko L.V.

Abstract

The problem of distortion of the autoregressive model of the voice signal under the influence of additive background noise in digital speech processing systems with data compression based on linear prediction is considered. In the frequency domain, these distortions are observed in the weakening of the main formants responsible for the intelligibility of the speaker’s speech. To compensate for formant attenuation, it is proposed to modify the parameters of the autoregressive model (linear prediction coefficients) using the impulse response of a recursive shaping filter. Along with the amplitude amplification of the formants, their frequencies remain unchanged to make the speaker’s voice recognizable. The effectiveness of the method was studied experimentally using specially developed software. Based on the experimental results, conclusions were drawn about a significant increase in the relative level of formants in the power spectrum of the corrected voice signal.

Radiotehnika i èlektronika. 2024;69(4):339-347
pages 339-347 views

Application of probing signals with zero autocorrelation zone for suppression of recurrent range interference in synthetic aperture radars

Ipanov R.N., Komarov A.A., Kozhevnikov K.Y., Permyakov S.V.

Abstract

The problem of overlap of echo signals of adjacent probing cycles in synthetic aperture radars (SARs), called range ambiguity interference, or recurrent interference, is considered, which is usually solved by using orthogonal linear frequency modulated (chirp) and phase-code shift keyed (PCSK) in adjacent SAR probing cycles, which allows you to successfully suppress false signals from bright point targets from adjacent repetition periods. For SAR, various types of probing PCSK signals with a zero autocorrelation zone are considered, which make it possible to successfully solve the problem of suppressing recurrent interference from both point targets and extended objects. A comparative analysis of the correlation characteristics of orthogonal chirp and PCSK signals with various types of PCSK signals with a zero autocorrelation zone has been carried out.

Radiotehnika i èlektronika. 2024;69(4):348-355
pages 348-355 views

Investigation of efficiency of DoA algorithm on the base of experimental data and numerical simulations in automotive distributed system of incoherent radars

Artyukhin I.V., Flaksman A.G., Rubtsov A.E.

Abstract

Investigation of efficiency of proposed DoA estimation algorithm for system of distributed incoherent automotive radars is performed on the base of experimental data and numerical simulation. It is shown that the proposed algorithm correctly recognizes the position of targets in considered experimental scenarios. Comparative numerical simulations show the efficiency of the proposed algorithm compared to the characteristics of single radar.

Radiotehnika i èlektronika. 2024;69(4):357-363
pages 357-363 views

Estimation of the required energy for a channel of high-precision phase direction finding of low-earth orbit space debris based on large scale antenna array

Baskakov A.I., Komarov А.А., Shimkin P.E.

Abstract

To solve the problem of radar observations of small-sized space debris of natural and artificial origin, a multi-antenna distributed structure based on adaptive antenna arrays is proposed. A method for estimating noise errors of the phase method of low-Earth orbit space debris bearing for a channel of high-precision phase direction finding based on elements of a multi-antenna field is presented. The results obtained characterize the potential accuracy of the system. Based on the specified dispersion of phase fluctuations, the required signal-to-noise ratio at the input of the device is determined according to the proposed method.

Radiotehnika i èlektronika. 2024;69(4):364-368
pages 364-368 views

Formation of cascaded Gordon–Mills–Welch sequences for digital information transmission systems

Starodubtsev V.G.

Abstract

Based on the modification of the algorithm for determining the decimation index vector, which is the main component of the Gordon—Mills—Welch sequence (GMWS) synthesis method, an algorithm for determining the decimation index vector A(l, m, n, r1, r2) for the synthesis of cascaded GMWS (CGMWS) with a period N = 2S — 1 = 2lmn — 1 (l > 2) in the GF[((2l)m)n] field by summing the sequences formed on the basis of decimation according to the obtained indices of the symbols of the basic M-sequence (MS). The modification of the algorithm consists in combining the vectors of the decimation indices for various combinations of the parameters r1 and r2 in the expression for the resulting vector. The results of calculating the maximum values of the equivalent linear complexity (ELC) of cascaded LCGMWS and conventional LGMWS GMWSs for periods 212–1 ≤ N ≤ 236–1 are presented. It is shown that the ELC of cascaded exceeds the ELC of conventional GMWSs, with an increase in the period the gain BS = LCGMWS/LGMWS increases, and for the period N = 236–1 it is equal to BS=36 = 2.25.

Radiotehnika i èlektronika. 2024;69(4):369-374
pages 369-374 views

ДИНАМИЧЕСКИЙ ХАОС В РАДИОФИЗИКЕ И ЭЛЕКТРОНИКЕ

Model of spatiotemporal coherent summation of ultra-wideband chaotic radio pulses formed by independent emitters

Zubkov A.S., Kuzmin L.V., Efremova E.V.

Abstract

A model of spatiotemporal summation of ultra-wideband chaotic radio pulses is proposed. The feasibility of using this model for analyzing scenarios of time-coherent radiation from independent sources of ultra-wideband chaotic radio pulses in wireless ultra-wideband systems is substantiated. Two scenarios are considered: where the distance between receiving point and emitters is much greater than the typical size of a group of emitters and where the receiving point is located between the emitters. Distributions of the total pulse energy in space for these scenarios are obtained.

Radiotehnika i èlektronika. 2024;69(4):375-384
pages 375-384 views

ПРИМЕНЕНИЕ РАДИОТЕХНИКИ И ЭЛЕКТРОНИКИ В БИОЛОГИИ И МЕДИЦИНЕ

Slidingan analysis of analytical signal of non-contact photoplethysmography for assessing heart rate

Labunets L.V., Lukin D.S., Ryakhina M.Y.

Abstract

The paper proposes a method for studying the variability of the subject’s heart rate based on the intellectual analysis of the pulse wave measured with remote photoplethysmography. The logically related stages of the formation of quadrature components based on the Hilbert transform of biomedical signals’ dynamics are presented. Within the framework of modern methods of intellectual analysis of non-stationary time series, realizations of adaptive estimates of instantaneous frequencies and periods of the heartbeat basic tone are obtained.

Radiotehnika i èlektronika. 2024;69(4):385-393
pages 385-393 views

ФИЗИЧЕСКИЕ ПРОЦЕССЫ В ЭЛЕКТРОННЫХ ПРИБОРАХ

Electroacoustic shear waves in the hollow structure of two piezoelectric

Afanasyev M.S., Vilkov E.A., Byshevsky-Konopko O.A., Chucheva G.V.

Abstract

Dispersion properties of electroacoustic waves in the gap structure of two different piezoelectrics are considered. It is shown that in the considered structure PbTiO3 – vacuum gap – BaTiO3 in the presence of a difference of shear wave velocities in piezoelectrics there are no purely symmetric and antisymmetric modes, and the coefficients of the boundary localization of the shear wave will be significantly different.

Radiotehnika i èlektronika. 2024;69(4):394-400
pages 394-400 views