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Determination of the Lunar Ground Properties with Polarimetric Radars Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2024-02-21 O. V. Yushkova
We present an analytical solution to the problem of determining a complex dielectric permittivity of ground based on bistatic Moon location results for the case where the measured values are the moduli of reflection coefficients of radio waves for vertical and horizontal polarizations and the difference in their phases.
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Parametric Resonance of the Non-Markovian Oscillator Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2024-02-09
We develop differential equations for the probability density of the phase coordinates of the dynamic systems with parametric fluctuations in the form of the non-Markovian dichotomic noise, which has arbitrary lifetime distribution functions in the states ±1. As an example, we calculate the first moment of the phase coordinate of the linear oscillator, whose perturbed motion is described by the stochastic
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Scattering of an Electromagnetic Wave by a Thin Perfectly Conducting Cylinder Located Inside a Dielectric Body Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2024-02-08 A. G. Dmitrenko, O. M. Balashova
We use the method of auxiliary sources to solve the problem of scattering of an electromagnetic wave in a thin perfectly conducting cylinder located inside a dielectric body. The specially developed computer code is briefly described. The results of calculating the scattering cross sections are presented for cylinders of different lengths located inside a dielectric sphere or a dielectric spheroid
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Interference of the Electric and Envelope Areas of Ultrashort Light Pulses in Quantum Systems Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2024-02-08 R. M. Arkhipov, M. V. Arkhipov, A. V.Pakhomov, O. O. Diachkova, N. N. Rosanov
In recent years, significant progress has been made in generating ultrashort electromagnetic pulses of single-cycle and subcycle duration. Unipolar pulses contain one half-cycle of the field and have a nonzero electric area. The conventional concepts of interaction of electromagnetic radiation with matter (in particular, interference) used in the case of multicycle pulses are not applicable to unipolar
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Single-Resonant Parametric Oscillator for Photons Compatible with Solid-State Quantum Memories Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2024-02-08
We present the results of spontaneous parametric down-conversion in a single-resonant optical parametric oscillator with PPLN crystal. The possibility of producing narrow-band single photons at a wavelength of 867 nm with a bandwidth of 19 MHz is shown. The latter makes this single-resonant parametric photon source compatible with solid-state quantum memories based on crystals doped with Nd3+ ions
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Longitudinal Waves in Structurally Inhomogeneous Viscoelastic Solids with a Quadratic–Bimodular Nonlinearity Decreasing with Increasing Frequency Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2024-02-08
We study theoretically the propagation of longitudinal acoustic waves in structurally inhomogeneous viscoelastic solids with a quadratic–bimodular nonlinearity decreasing with increasing frequency. Exact solutions for stationary waves propagating without changing their shape are obtained. Analytical and numerical solutions for the evolution of an initially harmonic wave are presented, and the amplitude–frequency
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Noise Direction Finding of Acoustic Sources by Using Microphone Antenna Arrays in the Presence of Intense Interference Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2024-02-08 A. A. Rodionov, V. Yu. Semenov
We consider the problem of passive acoustic direction finding with a linear microphone array in the presence of intense interference. It is assumed that a useful signal, as well as interference, is broadband and has an arbitrary time shape. It is also assumed that interference at various microphones differs only by the delay and amplitude. Such a scenario is realized when detecting a weak acoustic
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Interference of the Electric and Envelope Areas of Ultrashort Light Pulses in Quantum Systems Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2024-02-07 R. M. Arkhipov, M. V. Arkhipov, A. V.Pakhomov, O. O. Diachkova, N. N. Rosanov
In recent years, significant progress has been made in generating ultrashort electromagnetic pulses of single-cycle and subcycle duration. Unipolar pulses contain one half-cycle of the field and have a nonzero electric area. The conventional concepts of interaction of electromagnetic radiation with matter (in particular, interference) used in the case of multicycle pulses are not applicable to unipolar
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The Wave Mechanism of “Fast Breakdown” in Compact Intracloud Discharges Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2024-02-07 I. M. Kutsyk, L. P. Babich, E. I. Bochkov
We propose a wave mechanism for explaining “fast breakdown” in thunderstorm clouds and the generation of powerful pulses of electromagnetic radiation of very high frequencies (VHF, from 30 to 300 MHz). A polarization wave moves along the discharge gap; an area of increased electric field is formed at the wave front, inducing the transition of corona micro-discharges into streamers. The mechanism does
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Simulation of an Improved-Accuracy Monopulse Phase Direction Finder Based on an Adaptive Antenna Array Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2024-02-07 A. C. Popov, V. F. Pimenov
We present a mathematical formalization and the results of computer simulation of an angular phase discriminator, which employs a linear antenna array with adaptation according to the Howells–Applebaum algorithm. A method of improving the direction-finding accuracy of the radio-emission sources, which provides the measurement unambiguity with a considerable increase in the measurement baseline, is
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Topological Scalar and Vector Laser Solitons Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-12-19 N. A. Veretenov, N. N. Rosanov, S. V. Fedorov
We have compared the conditions of stability and the properties of topological scalar and vector (polarized) dissipative solitons in wide-aperture lasers with saturable absorber. In numerical simulations, vector solitons were formed by scalar solitons and even unstable scalar localized structures. Topological singularities and features of the dynamic regimes in lasers with isotropic and anisotropic
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Nonlinear Dynamics of Slipping Flows Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-12-19 E. A. Kuznetsov, E. A. Mikhailov, M. G. Serdyukov
We develop a new concept for the formation of behavior features of inviscid incompressible fluids on the rigid boundary due to breaking of slipping flows. The breaking possibility is related to the compressibility of such flows due to the boundary. For two- and three-dimensional inviscid Prandtl equations, we analytically obtain the criteria for a gradient catastrophe for slipping flows. For the two-dimensional
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Polariton Phenomena in Superradiant Lasing with a Low-Q Asymmetric Fabry–Perot Cavity Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-12-14 E. R. Kocharovskaya, Vl.V. Kocharovsky
We study polariton phenomena and the mechanism of self-modulation of a highly asymmetric state of the active medium and field in a superradiant laser with a low-Q Fabry–Perot cavity based on the numerical solution of the semi-classical Maxwell—Bloch equations. Features of the predicted dissipative superradiant state arising due to the formation of an inhomogeneous self-consistent population-inversion
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Theoretical Analysis of the Stability of the Single-Mode Generation Regime in the Gyrotron Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-12-14 A. B. Adilova, N. V. Grigoryeva, A. G. Rozhnev, N. M. Ryskin
We discuss the question of the stability of the single-mode generation regime in the gyrotron. An example of a gyrotron with the fixed Gaussian structure of the high-frequency field is used to analyze theoretically the instability mechanism during the interaction of modes with the quasiequidistant spectra on the assumption that the amplitudes of the spurious modes are low. The boundaries of the stability
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Simulation of Nonlinear Processes in High-Q Microresonators in the Self-Injection Locking Regime with Account of Thermal Effects Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-12-14 V. I. Pavlov, N. M. Kondratiev, V. E. Lobanov
The thermal effects appearing inevitably when laser radiation propagates through high-Q optical microresonators lead to various drifts, fluctuations and unstable regimes. In particular, thermal effects can affect strongly the generation of optical frequency combs and dissipative soliton structures. A way to offset the thermal effects is to use the self-injection effect that locks the laser radiation
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Synchronization of Metastable Oscillations Arising in the Evolutionary Game of Two Populations Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-12-14
We study the forced synchronization of cyclic stochastic oscillations with a finite lifetime (metastable oscillations). A mathematical model of the battle of the sexes evolutionary game is considered as an example. The model describes the competition between the strategies for selecting a partner and raising offsprings in two populations of the opposite gender. For a system under the influence of a
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Linear and Nonlinear Aspects of Climate Response to External Forcings Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-12-13 A. V. Eliseev
The main role in the current climate change is played by anthropogenic forcings, primarily anthropogenic emissions of greenhouse gases and aerosols. On the global scale, the response of the Earth system to these forcings is close to linear. In particular, it depends mostly on the magnitude of such forcings and only weakly on their nature and spatial localization. However, even with relatively small
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On the Stretching of Mesoscale Vortices into Filaments and their Distribution over the Ocean Surface Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-12-13 V. V. Zhmur, T. V. Belonenko, E. V. Novoselova, B. S. Suetin
We consider various aspects of interaction of vortices with a barotropic flow. When a vortex interacts with a flow, there exist three variants of the flow-core behavior: rotation, nutational oscillations, and unlimited stretching. In the first two cases, the vortex remains a localized formation, such that the ellipse semiaxes undergo oscillations near certain average values. In the third case, the
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Two Ways to Generalize Gerstner Waves in the Theory of Waves in Deep Water Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-12-13 A. A. Abrashkin, E. N. Pelinovsky
By convention, water waves are studied under the assumption of their potentiality. This approximation is not always valid in natural conditions. The vorticity is introduced by shear currents, which are ubiquitous in the ocean. It is also generated in the near-surface layer as a result of wind action. When these factors are taken into account, the models developed for potential waves require refinement
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On the Influence of Microbubbles on the Turbulence Induced by a Surface Wave Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-12-13 O. A. Druzhinin
We use the direct numerical simulation (DNS) method to study the vortex structure of the near-surface water layer, which is saturated with air bubbles, in the presence of a stationary surface wave. A wave with a wavelength of 15 cm and a steepness of 0.2 (an amplitude of about 0.5 cm) and bubbles 400 μm in diameter (microbubbles) are considered. Complete three-dimensional fluid motion equations (Navier–Stokes
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Multi-Barrel Gyrotron for DNP/NMR Spectroscopy Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-10-16 V. E. Zapevalov, A. S. Zuev, O.P.Plankin, E. S. Semenov
We consider an example of implementation of a multi-barrel gyrotron. The simplest scheme of the multi-barrel gyrotron combines the advantages of both the canonical gyrotron and the gyrotron with the near-axis beam as the system of formation of helical electron beams and efficient selection of modes synchronous with high gyrofrequency harmonics, respectively, and is attractive from the viewpoint of
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On the Problem of Inhomogeneous Spatial Distribution of the Redox Index of Polyvalent Iron Ions in the Volume of Ultrapure Synthetic Quartz Materials Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-10-10 K. V. Vlasova, A. I. Makarov, N. F. Andreev
We show that the strong spatial inhomogeneity of absorption (the change from the maximum to the minimum value was more than 50 times on a spatial scale of the order of 200–300 μm), which was observed in our earlier studies of ultrapure synthetic quartz glasses and a synthetic quartz crystal at a wavelength of 1070 nm, can be related to an inhomogeneous spatial distribution of the redox state of iron
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Coulomb and Quantum Interference Effects in the Spectra of High-Order Harmonics Generated by Aligned Molecules Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-10-10 A. D. Slyusareva, M. Yu. Emelin, A. S. Emelina, M. Yu. Ryabikin
We study theoretically the features of the spectra of high-order harmonics of laser radiation generated in an ensemble of aligned diatomic molecules outside the framework of the strong-field approximation. The studies were carried out on the basis of numerical calculations within the framework of a model given by a two-center generalization of the Yukawa potential. Influence of the interference of
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Bifurcations and Chaos in Open Quantum Systems Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-10-10 I. I. Yusipov, S. V. Denisov, M. V. Ivanchenko
A study of open quantum systems and dynamical regimes that emerge in such systems is an actively developing field of the theoretical and experimental physics. Although the bifurcation analysis and the theory of dynamical chaos are very important branches of nonlinear dynamics, their use for describing the processes occurring in open dissipative quantum systems has been restricted until recently. In
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Excitation of Electromagnetic Oscillations of a Dielectric Ball by a Complex Oscillation of a Radial Dipole Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-10-10 G. F. Zargano, A. V. Kharlanov
We consider excitation of electromagnetic oscillations of a homogeneous dielectric ball by a radial dipole, oscillations forming a periodic sequence of radio pulses. It is shown that at high frequencies the field distribution is close to the field distribution of the eigenoscillations corresponding to these frequencies, whereas the neighboring harmonics also have an impact at low frequencies. It is
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Observation of Excitation of Eigenmodes in Surface-Wave Resonators Having the Cylindrical Geometry Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-10-10 V. Yu. Zaslavsky, M. D. Proyavin, D. I. Sobolev, I. V. Zheleznov, A. M. Malkin, A. S. Sergeyev, V. E. Kotomina, A. A. Orlovsky, N. S. Ginzburg
We present the results of theoretical and experimental studies of the surface-wave Ka-band resonators which are formed by sections of cylindrical waveguides with single-period wall corrugations. The electrodynamic characteristics of such resonance cavities are analyzed within the quasioptical approach and three-dimensional simulation by the finite-difference time-domain method. The results of the theoretical
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Experimental Study of Terahertz Radiation Generation in the Interaction of Ultrashort Laser Pulse with Gas Targets Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-09-28 R. S. Zemskov, S. E. Perevalov, A. V. Kotov, S. B. Bodrov, A. N. Stepanov, A. A. Solov’ev, M. I. Bakunov, A. G. Luchinin, V. N. Ginzburg, A. A. Kuz’min, I. V. Yakovlev, S. E. Stukachev, A. A. Kochetkov, I. A. Shaikin, A. A. Shaykin, E. A. Khazanov, M. Yu. Glyavin, N. V. Chekmarev, A. V. Vodop’yanov, M. V. Starodubtsev
We present the first experimental results obtained with a setup created on the basis of the PEARL laser facility for studying the processes of generating terahertz radiation from laser wake fields which are formed during the propagation of a high-power femtosecond laser pulse in a rarefied plasma. In particular, the occurrence of terahertz generation in the case where the laser–plasma interaction region
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Two Methods of Target Detection in an Automotive Radar Against the Background of its Own Noise Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-09-28 V. T. Ermolaev, V. Yu. Semenov, I. V. Artukhin
We consider the problem of simultaneous detection of close and distant targets in an automotive millimeter-wave radar. Two approaches for solving the problem are proposed. The first approach is based on the subtraction of more powerful signals in the time domain and the subsequent detection of less powerful signals. The second approach is based on the most plausible estimate of the impulse response
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Absorption of a Narrow-Band Signal in a Dispersive Medium Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-09-28 N. S. Bukhman
We consider propagation and absorption of a narrow-band signal in a homogeneous dispersive medium. It is shown that all signals can be divided into two qualitatively different classes, namely, holonomic and piecewise-holonomic signals. When propagating in an absorbing medium, the holonomic signals are attenuated obeying an exponential law and, therefore, almost disappear at a sufficient long path lengths
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Adaptive Processing of a Set of Signals in Antenna Arrays with Extended Reception Band Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-09-28 N. M. Ivanov, V. N. Shevchenko
We propose a method of multisignal adaptive spatial filtering, which generalizes the classical method of adaptive spatial filtering of a single signal with a known arrival direction. Additionally, the formulas for the modified Capon direction-finding method are found. Reliability of the relationships, which are obtained on the basis of the maximum-likelihood method, is confirmed by the limiting transitions
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Čerenkov Radiation of an Ultrashort Laser Pulse Propagating in a Strongly Magnetized Plasma at Various Intensities and Directions of the Magnetic Field Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-09-28 A. D. Sladkov, A. V. Korzhimanov
We study generation of Čerenkov radiation by an ultrashort laser pulse propagating in the magnetized plasma across an external magnetic field basing on the analysis of the dispersion relation and numerical simulation in the case where the cyclotron frequency exceeds the plasma frequency. It is shown that the radiation with a frequency in the range from the plasma frequency to the cyclotron one and
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Pulses of the Electromagnetic Field with a Non-Zero Electric Area Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-09-28 A. B. Plachenov, N. N. Rozanov
We analyze the possibility of existence of electromagnetic-field pulses with a non-zero electric area (time integral of the electric field) within the framework of the Maxwell equations. It is demonstrated that in the absence of charges and currents in vacuum, the non-zero electric area of a pulse would lead to its infinite energy. A pulse with the non-zero area is shown to form already in the case
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Plasma-Chemical Facility for Synthesis of Micro- and Nanoparticles Having Controlled Compositions and Structures on the Basis of a Microwave Discharge in the Gyrotron Radiation Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-09-11 A. S. Sokolov, N. S. Akhmadullina, V. D. Borzosekov, E. V. Voronova, T. É. Gayanova, N. G. Gusein-zade, Z. A. Zakletskii, A. K. Kozak, D. V. Malakhov, N. N. Skvortsova, V. D. Stepakhin, E. A. Obraztsova, O. N. Shishilov
We present a description of a plasma-chemical facility designed for synthesis of micro- and nanoparticles using the radiation of a high-power gyrotron. The facility has been developed at the Plasma Physics Division of A.M.Prokhorov General Physics Institute of the Russian Academy of Sciences. The facility includes a plasma-chemical reactor, a gyrotron unit, an in-line calorimeter, a diagnostic system
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Measurements of the Atmospheric Electric Current Density by a Passive Horizontal Ring Antenna in the Surface Layer: Quasi-Stationary Approximation Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-09-11 S. V. Anisimov, S. V. Galichenko, A. A. Prokhorchuk, K. V. Aphinogenov, E. V. Klimanova
We consider a quasi-stationary approximation for turbulent electrical processes in the atmospheric boundary layer and their recording by a passive horizontal ring antenna acting as a collector of atmospheric electric current. On the basis of large eddy simulation, variations in electrical variables are calculated and spatial correlation functions and the spectral density of fluctuations of the atmospheric-current
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Creation of a HF and VHF Radio Communication Channel Through an Artificial Ionospheric Repeater Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-09-11 V. P. Uryadov, F. I. Vybornov
We study experimentally the possibility of creating a HF and VHF radio communication channel at frequencies above the hop-by-hop MUF through an artificial ionospheric repeater, which is formed by as scatterers in the form of magnetic field-aligned small-scale artificial ionospheric irregularities, created at the altitudes of reflection of a high-power O-mode pump wave. The experiments were carried
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Source Localization in a Channel with a Rough Surface Using a Multi-Rank Capon Algorithm Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-09-11 A. G. Sazontov
We consider the problem of acoustic source localization in a shallow water channel, in which the prevailing mechanism of sound scattering is developed wind seas. For the given scenario, an adaptive multi-rank Capon algorithm, which is capable of processing in both the conventional and mode space and localizes the source under conditions of incomplete information on a random propagation channel, is
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Estimation of the Variance of a Random Signal with an Unknown Frequency Bandwidth Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-09-08 Yu. E. Korchagin, M. M. Turbin, K. D. Titov
We consider the problem of estimating the variance of a Gaussian stationary stochastic signal with a regular spectral density and a priori unknown frequency bandwidth. Two methods for overcoming an a priori uncertainty are proposed, namely, the quasi-likelihood algorithm and the joint maximum-likelihood estimation of all unknown parameters. The structural schemes are developed and the estimation characteristics
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Mechanically Machined Microwave Multi-Layer Antireflective Coating of a Dielectric Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-09-08 A. V. Ryabov, D. I. Sobolev, M. Yu. Shmelev
We present theoretical and experimental results on mechanically machined multilayer antireflective coating of a dielectric plate. The microwave ouptut window made of fluoroplast with the refractive index n = 1.41, was studied experimentally. Holes of two different diameters were drilled in a honeycomb pattern on the surface of the dielectric to different depths in such a way that two thin quarter-wave
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Measurements of the Atmospheric Electric Current Density by a Passive Horizontal Ring Antenna in the Surface Layer: Electrostatic Approximation Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-07-15 S. V. Anisimov, S. V. Galichenko, A. A. Prokhorchuk, K. V. Aphinogenov
We study analytically and numerically the relationships for a passive horizontal ring antenna, which is used as a collector for long-term observatory measurements of the atmospheric electric current density. The spatial distributions of the potential and the electric field as functions of the geometric characteristics of the antenna, which is located in a uniform atmospheric electric field, are determined
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Deceleration and Self-Compression of a Wave Pulse in a Discrete Medium Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-07-15 A. G. Litvak, V. A. Mironov, L. A. Smirnov, A. O. Sofonov
We consider the features of the dynamics of the wave-packet self-action within the framework of a model described by the one-dimensional discrete nonlinear Schrödinger equation with allowance for the effects of acoustic relaxation of the nonlinear response of the medium. Such models are actively used to describe the energy transfer along protein molecules. Analytical and numerical studies show that
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Propagation of Pulsed Electromagnetic Signals with the Axisymmetric Field Structure in a Nonlinear Nondispersive Medium Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-07-15 A. V. Kudrin, E. Yu. Petrov
We consider the propagation of pulsed electromagnetic signals with the axisymmetric field structure in a nonlinear nondispersive medium. It is also assumed that in the linear limit (for small amplitudes of the field components), an axisymmetric inhomogeneity of dielectric permittivity can be present in the considered model of the medium. A rigorous solution for the problem of the behavior of the pulse
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On the Possibility of Advancement of the Non-Stationary Gas Spectroscopy Method Realized by Using Fast Frequency Sweep Mode Up the Terahertz Frequency Range Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-07-14 V. L. Vaks, V. A. Anfertev, M. B. Chernyaeva, E. G. Domracheva, S. I. Pripolzin, A. N. Baranov, R. Teissier, A. A. Ayzenshtadt, K. A. Gavrilova
Fast frequency sweep mode is a promising method for spectrum recording in a sufficiently wide frequency range within a short time (about a few milliseconds). This approach permits one to detect all substances which have intense absorption lines lying in the frequency range of the spectrometer and which are in a gas mixture when the spectrum is recorded. A spectroscopic system consisting of spectrometers
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Potentialities of Small-Size Subterahertz-Wave Spectrometers Based on Cascade Frequency Multiplication for Local Environmental Monitoring of the Atmosphere Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-07-14 Yu. V. Kistenev, A. Cuisset, F. Hindl, G. K. Raspopin, V. L. Vaks, E. G. Domracheva, M. B. Chernyaeva, A. I. Karapuzikov
We discuss various approaches to designing a small-size subterahertz-wave spectrometer based on the effect of cascade frequency multiplication, which can be used for local environmental monitoring of the atmosphere under field conditions. The results of estimating the limit of detection by the absorption coefficient are presented along with information about the optimal ranges and limits of detection
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On Atmospheric Absorption Values at Millimeter Waves on the Suffa Plateau and Karadag Landfill Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-07-14 I. T. Bubukin, I. V. Rakut, M. I. Agafonov, A. L. Pankratov, A. V. Lapinov, L. Yu. Petrov
We present the results of a comparative analysis of the available atmospheric absorption data for millimeter waves on the Suffa plateau (southern Uzbekistan). It is shown that the atmospheric absorption values at wavelengths of 3 and 2 mm published in G. Bubnov, et al., EPJ Web of Conferences 195, 09002 (2018) are much smaller than the data obtained for the Suffa site according to other sources. The
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Features of Using the Quadrature Amplitude Modulation for Forming the Directional Pattern of an Active Phased Antenna Array Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-06-26 M. M. Gavrilov, A. A. Zorina, Z. P. Kupriyanov, P. V. Kupriyanov, S. A. Silaev
We consider technical aspects of using quadrature amplitude modulation in modern microwave active phased antenna arrays. A necessity of improving the accuracy of phase adjustment for realizing complex types of the amplitude-phase distribution of signals in the antenna aperture, which is required for forming the directional patterns with a low level of side lobes, is substantiated. Special attention
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A Method for Estimating the Changes in the Directions of the Main Maxima of the Directional Pattern of a Multibeam Antenna in the Problem of Passive Direction Finding Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-06-26 Yu. E.Chumankin, V. R. Fidelman, O. A. Morozov
We propose a method for calculating the displacements of the main maxima of the directional-pattern beams of a reflectory multibeam antenna, which are related to the reflector deformation, and estimate its accuracy. To describe the deformation, we use the model of the displaced and rotated reflector of a perfect calculated form, which agrees with the form of the deformed reflector in the sense of the
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Reflecting Properties of the Seasonally Thawed Layer during Thawing and Freezing of the Light Loam Soil. Numeric-analytical Study Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-06-26 K. V. Muzalevsky
We use numeric-analytical methods to study theoretically the reflective properties of the layered media of the seasonally thawed active layer (AL) in the process of their freezing and thawing in the ultrawide frequency band from 10 MHz to 10 GHz, as well as the process of interaction of 2.5-ns ultrawide band pulses in the megahertz frequency range with such media, for the light loam soil with the clay-fraction
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Electromagnetic Field in the Upper Ionosphere Fromhorizontal ELF Ground-Based Transmitter of Finite Length Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-06-26 E. N. Fedorov, N. G. Mazur, V. A. Pilipenko
We consider the feasibility of detection of electromagnetic response in the upper ionosphere to ground-based large-scale extremely low-frequency (ELF) transmitters by low-orbiting satellites. As an example of such mega transmitters, we consider the ZEVS 82-Hz transmitter and the FENICS facility with decommissioned electric power lines driven by an 0.5–100 Hz oscillator. We numerically simulated the
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Radiation of Nonsymmetric Whistler Waves from a Phased Antenna Array in a Magnetoplasma Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-06-26 E. V. Bazhilova, T. M. Zaboronkova, A. S. Zaitseva, A. V. Kudrin
We study the radiation of nonsymmetric waves from a circular equidistant phased antenna array immersed in a homogeneous cold magnetoplasma. The radiating elements of the array are electrically small loop antennas the axes of which are aligned with an external magnetic field. By expanding the excited field in terms of cylindrical vector eigenfunctions of the magnetoplasma, integral representations of
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Improving the Resolution of Diagnostics of Inhomogeneous Plasma Media Using Spatial Field Processing with Due Regard to Multipath Effects Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-06-26 S. I. Knizhin, M. V. Tinin
We consider the problem of eliminating the effect of multipath radio wave propagation in inhomogeneous plasma media by additional spatial processing of field measurements. This field processing is based on the Double Weighted Fourier Transform (DWFT). The calculations are made for cases of multipath propagation due to radio wave refraction by plasma focusing and defocusing lenses for ionospheric and
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Methods for Correction of the Altitude Electron-Density Profiles of the IRI Model for the Bottomside Ionosphere from Satellite Sounding Data Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-06-26 P. F. Denisenko, V. V. Sotsky
We offer a comparative analysis and a brief description of three methods for reconstruction of altitude dependences of the ionospheric electron density from topside satellite ionograms containing traces of sounding signal reflections from the Earth’s surface. In all methods, topside profiles are calculated from the x trace of the ionogram in the classical way. To reconstruct the electrondensity profiles
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Distribution Functions of Eigenvalues of the Sample Correlation Matrix of an Antenna Array Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-06-01 O. E. Kudryashova, E. S. Fitasov
We obtain an analytical expression for the cumulative distribution functions of all eigenvalues of the sample correlation matrix of inherent noise in the antenna-array elements for the multidimensional case. We also find the formula for distribution of all noise eigenvalues of the sample correlation matrix of the antenna-array signals in the presence of inherent noise and an arbitrary number of high-power
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Stabilization of the Radiation Frequency of a Gyrotron with a Remote Reflector Under the Conditions of Interaction of the Equidistant-Spectrum Modes Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-05-31 V. L. Bakunin, G. G. Denisov, A. N. Kuftin, Y. V. Novozhilova, A. P. Fokin, A. S. Zuev, E. S. Semenov
We study the possibility to stabilize the gyrotron frequency under the influence of a wave reflected from a remote output window during the competition of the operating mode with two neighboring modes, which have frequencies equally spaced from the frequency of the operating mode. The window is assumed to reflect radiation at the frequency of the operating mode and be transparent for the neighboring
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Diagnostic Capabilities of a Microwave Resonator Probe for Studies of the Parameters of a Nonstationary Magnetoplasma Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-05-31 A. G. Galka, M. S. Malyshev, A. V. Kostrov
We present the experimental results of developing the method for measurements of the parameters of a magnetoplasma using a microwave resonator probe based on a section of a two-wire line and aligned with an external magnetic field. It is found that the probe resonance is determined by the plasma refractive index for an extraordinary wave. The fact that the measuring system has two resonances at frequencies
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Analysis of the Turn-On Delay of Quantum Cascade Lasers Under Pumping with a Trapezoidal Current Pulse Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-05-31 K. V. Kusakina, G. S. Sokolovsky
We analyze the turn-on delay of quantum cascade lasers (QCLs) under pumping with a trapezoidal current pulse. The simulation is based on a system of rate equations for a three-level laser system. We identify five QCL regimes, for which appropriate analytical formulas for the turn-on delay estimation are obtained. The analytical results are in good qualitative agreement with numerical simulations. It
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Nonstationary Dynamics of a Bipolarized Nd:YAG Laser with a Fabry–Perot Cavity Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-05-31 P. A. Khandokhin
We study experimentally the fluctuation and dynamic behavior of a bipolarized microchip Nd:YAG laser. A nonstationary behavior similar to that predicted in [1] was detected. The self-modulation frequency was close to the frequency of relaxation oscillations typical of solid-state lasers. According to the data available to us, this was the first study (observation) of such a behavior.
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Transition of an Ensemble of Radiative Oscillators to the Dark State when Interacting with a Resonant Dissipative Subsystem Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-05-30 M. D. Tokman, M. A. Erukhimova
We theoretically study a fairly universal effect of screening the quantum states of an optical field from interaction with the system as a result of excitation of the modes initially being in the ground (vacuum) state. The cases of two-level and harmonic perturbing subsystems are considered. In the case of a sufficiently large number of “screening” modes, the formation of the corresponding dark state
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Study of Josephson Generation Harmonics in a Long Josephson Junction Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-05-30 N. V. Kinev, K. I. Rudakov, L. V. Filippenko, V. P. Koshelets
We present the results of experimental study of the harmonics of Josephson radiation from a terahertz (THz) source based on a long Josephson junction (LJJ). The source consists of an integrated circuit including the LJJ, a matched transmitting antenna, and a harmonic mixer used for phase locking of the output signal. The LJJ and the harmonic mixer are both made of three-layer Nb-AlOx-Nb supercondu
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Synthesis of an Ultra-Wideband Pulse by a Log-Periodic Antenna with Continuous Excitation by Harmonic Oscillations Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-05-30 K. V. Muzalevsky
We propose a method for synthesizing ultra-wideband pulses using a vector network analyzer and a wideband transceiving log-periodic antenna. The transfer characteristic of the antenna-feeder transmission line of the system is described by the model of a two-port network whose S-matrix elements are calibrated for at least two heights of the antenna above the reflecting surface (metal plate). The proposed
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Phase-Difference Approach for GNSS Global Ionospheric Total Electron Content Mapping Radiophys. Quantum Electron. (IF 0.8) Pub Date : 2023-04-22 A. M. Padokhin, E. S. Andreeva, M. O. Nazarenko, S. A. Kalashnikova
The paper proposes an ingenious method for global ionospheric total electron content (TEC) mapping based on a phase-difference approach to the analysis of phase measurements of GNSS signals at a pair of coherent frequencies on a distributed network of ground-based receivers of the global IGS network. The proposed approach uses the representation of the ionosphere as a thin layer with the TEC distribution