Vol 23, No 3 (2020)


Entanglement of atoms induced by thermal noise in the presence of initial atomic coherence

Bashkirov  E.


In this article, author investigated the dynamics of entanglement of two dipole-coupled natural or artificial two-level atoms (qubits) interacting nonresonantly with the intensive one-mode cavity thermal field. Author found an exact solution of the quantum Liouville equation for the full density matrix of the system «two atoms + field mode» for a coherent initial state of atoms in the «dressed states» representation. The full system density matrix is used to calculate the two-atom reduced density matrix and to calculate the quantitative criterion for atom-atom entanglement ‒ negativity. The results of computer simulation of the time dependence of negativity showed that in the case of a model with nonresonant interaction, the presence of initial atomic coherence leads to a significant decrease in the maximum degree of atomic entanglement, in contrast to the model with resonant interaction of atoms and a field. For the resonance model, the initial atomic coherence greatly enhances the degree of atomic entanglement.

Physics of Wave Processes and Radio Systems. 2020;23(3):10-17
pages 10-17 views

Generation of optical signals carrying OAM based on vortex fiber-optic periodic structures

Gizatulin A.


In this article, author considers the process of generation of fiber modes carrying orbital angular momentum (vortex modes) using chiral fiber Bragg gratings; in this context, the formation of vortex modes is carried out by converting the fundamental mode into higher order modes. Within the framework of the article, a generalized mathematical model of chiral fiber Bragg gratings is presented, which includes an arbitrary function of apodization and chirping, which makes it possible to calculate gratings that form vortex modes of a given order for the required frequency range with the required reflection coefficient. In addition, a matrix method for describing chiral fiber Bragg gratings is proposed, based on the mathematical apparatus of the coupled modes theory and scattering matrices. This matrix approach is convenient for describing complex and / or cascaded gratings. In addition, in this work, simulation of the considered fiber structures is carried out.

Physics of Wave Processes and Radio Systems. 2020;23(3):18-26
pages 18-26 views

Four-wave interaction in a multimode waveguide with a thermal nonlinearity in a circuit with codirectional pumping waves

Ivakhnik V., Kapizov D., Nikonov V.


The spatial selectivity of a four-wave radiation converter in a multimode waveguide with thermal nonlinearity in a circuit with incident pump waves is analyzed. It is shown that the half-widths of the modulus of the point spread function, which characterizes the image conversion quality, are mainly determined by the transverse dimensions of the waveguide. With an increase in the angle of incidence of the pump waves on the front face of the waveguide, it decreases both the maximum value and the half-width of the modulus of the point spread function. The recording of two temperature gratings in the waveguide leads to a modulation of the point spread function with a period inversely proportional to the angle of incidence of the pump waves.

Physics of Wave Processes and Radio Systems. 2020;23(3):27-33
pages 27-33 views

On the convergence the barycentric method in solving diffraction problems on conductive thin screens

Il’inskii A., Polyanskii I., Stepanov D., Kuznetsov N.


Annotation – In this article, the use of the barycentric method is proposed for the numerical solution of problems of diffraction of electromagnetic waves on infinitely thin perfectly conducting screens of arbitrary shape. The numerical solution is formed in the projection formulation of the Galerkin method. The essence of the barycentric method is to form a global system of basic functions for opening the screen when determining the approximation of the desired function of the current plane on its surface. Basis functions are defined by Bernstein-type polynomials in terms of barycentric coordinates that are entered for opening the screen when it is represented as a closed simply connected polygonal region. The features of the algorithmic implementation of the barycentric method in solving diffraction problems on conducting thin screens are considered. The rate of convergence is estimated. Comparative results of calculations performed under equivalent conditions using the barycentric method and the RWG method are presented.

Physics of Wave Processes and Radio Systems. 2020;23(3):34-43
pages 34-43 views

Research of electromagnetic characteristics of planar chiral metastructures based on composite helices components taking into account the heterogeneous Bruggeman model

Aralkin M., Dement’ev A., Osipov O.


In this work a mathematical model of a chiral metamaterial is constructed which based on composite fine-wire helices components, which takes into account the properties of chirality, heterogeneity and dispersion. When constructing the model the chiral metamaterial was considered as a heterogeneous system and described by the Bruggeman model. In this work, analytical relationships were obtained for calculating the resonance frequencies of composite helices components. The dispersion properties of the metamaterial were described using the well-known Condon model. As an example of using the constructed mathematical model, we solved the problem of the reflection (transmission) of a plane electromagnetic wave of linear polarization from a planar layer of the chiral structure under study based on composite helices microelements. A system of linear algebraic equations was obtained to determine the reflection and transmission coefficients of the main and cross-polarized field components. As a result of the numerical simulation, the frequency-selective properties of the metastructure were discovered and the frequencies at which the electromagnetic wave is «captured» by the planar layer of the metastructure were revealed. A similar effect can be used to creation of frequency selective concentrators (hubs) of microwave energy.

Physics of Wave Processes and Radio Systems. 2020;23(3):44-55
pages 44-55 views

Thin-wire radiating structures with double symmetry

Tabakov D., Morozov S., Kurakov V.


The problems of electrodynamic analysis of thin-wire radiating structures with double symmetry are considered. New generalized integral representations of the electromagnetic field are obtained for the case of structures with single and double symmetries. Based on the obtained expressions, mathematical models of two - and four-way elliptical spiral antennas are constructed. It is shown that taking into account double symmetry in solving the internal electrodynamic problem leads to a set of independent Fredholm integral equations of the first kind written with respect to the distributions of normal current waves, which significantly simplifies the solution of the internal electrodynamic problem. Comparisons of current distributions along conductors, their input resistance dependences on the radius of the structure, and normalized radiation patterns for two- and four-way spiral emitters are presented.

Physics of Wave Processes and Radio Systems. 2020;23(3):56-61
pages 56-61 views

Parameters of the electric strength of air in a surface antenna during the emission of an ultrahigh-frequency pulse with a trapezoidal envelope

Volkov A.


On the basis of the breakdown criterion and the equation of continuity of electrons in air, the amplitude and energy parameters of the electric strength of air in the surface antenna of a powerful microwave relativistic generator are determined when pulses are emitted with a trapezoidal envelope. Triangular and rectangular envelopes were considered as boundary cases of a trapezoidal envelope. The dependence of the parameters of electric strength on the shape of the envelope has been established. The calculation of the dependences of the breakdown field and the maximum permissible energy in a flat aperture on the pulse duration in the range of realizable durations of powerful relativistic microwave generators is carried out. For the same duration, the largest breakdown field has a pulse with a triangular envelope, and the smallest – a pulse with a rectangular envelope. Wherein a pulse with a triangular envelope has the lowest maximum permissible energy, and a rectangular one has the highest. The relationships between the maximum permissible energy and the breakdown field for the pulses under consideration are determined. With the same maximum permissible peak amplitude, the highest energy has a pulse with a triangular envelope, and the smallest – a pulse with a rectangular envelope.

Physics of Wave Processes and Radio Systems. 2020;23(3):62-67
pages 62-67 views

Features of the development of broadband frequency mixers with suppression of the mirror channel in the range frequencies 9–27 GHz

Uglov G., Belova Y.


The article is devoted to features of the development two types of broadband frequency mixers with image channel suppression in the frequency range 9–27 GHz. The purpose of the study is to determine the optimal ways to solve the problem of modeling complex multifunctional microwave units. The article discusses the development process of such functional units as the local oscillator amplifier, low-noise amplifier and frequency mixer. Comparisons of the calculated characteristics with the results of measurements of the manufactured models of the samples are given. Attention is also paid to the technology of manufacturing field-effect transistors, resistors and capacitors that are part of the functional units of the frequency mixer. The scientific novelty lies in the uniqueness of the product development, which includes several functional units on one crystal. As a result, two types of frequency mixers with suppression of the mirror channel in a package design have been created, which, in terms of their characteristics, can replace similar foreign products from Analog Devices.

Physics of Wave Processes and Radio Systems. 2020;23(3):68-73
pages 68-73 views

Research the load capacity of microcircuits

Yarantseva K., Shopin G., Piganov  M., Andrusenko V.


The device for the definition of the integrated circuits load-driving capability is offered. Device for determining the output capability of microcircuits refers to the field of microminiaturization and the technology of radio electronic equipment and can be used to control the parameters of microcircuits during their production. The device contains a rectangular pulse generator, an integrated circuit that is being tested, a repeater, load, a switch, an AND gate, a comparator, a pulse counter and a voltage reference, a vibrator, a reversible pulse counter, a decoder, and an indicator. Technical result when implementing the disclosed solution is high accuracy and reliability of determining load capacity of microcircuits. The proposed device allows increasing accuracy and reliability of defining circuit’s load-driving capacity. It also allows testing of TTL, Schottky-TTL, and MOSFET circuits. There are two switchable operating modes for testing fan-out for logical high and low levels. It is easy to replace a circuit that is being tested and load.

Physics of Wave Processes and Radio Systems. 2020;23(3):74-81
pages 74-81 views

Modified DRM+ signal generation algorithm with reduced crest factor

Morozov K.


To reduce the crest factor in the DRM+ system due to the limitations imposed by the standard the peak limiting method (clipping) and the window weighting method, which are based on signal distortion, are widely used. As a result of the application of these methods out-of-band emissions in the signal spectrum significantly increase. After filtering out-of-band emissions the effect of a repeated increase in the crest factor appears. In this regard, there is an urgent scientific and technical problem of finding the optimal method for filtering out-of-band emissions of the DRM+ signal. The purpose of this article is to analyze the existing methods for filtering out-of-band emissions in the process of reducing the crest factor in a DRM system, as well as choosing the optimal filtering algorithm after reducing the crest factor for DRM+ transmitters. A method for suppressing out-of-band emissions using a digital filter based on FFT / IFFT is considered. The modeling of the proposed algorithm for filtering the signal by the mask of out-of-band emissions is carried out. Comparative studies of the method of the standard filtering algorithm and the proposed algorithm are carried out; the high efficiency of the latter is shown. The results obtained will improve the efficiency of reducing the crest factor in broadcasting transmitters of the DRM + standard, thereby increasing their power efficiency.

Physics of Wave Processes and Radio Systems. 2020;23(3):82-89
pages 82-89 views

Electromagnetic compatibility in CNC machines upgrade

Antonov A., Danilaev  D.


Abtract – One of the types of modernization of CNC machines is the replacement of outdated electronic control units with more functional and compact ones, made on a modern element base. However, in the course of work on the modernization of CNC machines, characteristic problems of electromagnetic compatibility arise. The report examines the features of the electromagnetic compatibility of equipment, blocks and assemblies of CNC machines during modernization. Based on the analysis of the factors characterizing the electromagnetic environment, typical failures of the electronic part of the control system of a CNC machine tool during testing, the need for the development of measures to ensure EMC is shown. All measures to ensure electromagnetic compatibility are not intended to reduce degradation, but to ensure the full implementation of all equipment functionality. General solutions are proposed that are applicable to the modernization of most second-generation CNC machine tools.

Physics of Wave Processes and Radio Systems. 2020;23(3):90-96
pages 90-96 views

Algorithm for conducting autonomous tests of radio electronic means

Bykov A.


Due to the increasing complexity of radio electronic equipment, the problem of its reliability becomes much more acute. At the same time, the task of evaluating on-board equipment at the design and production stages becomes very urgent. An important issue is also the reliable determination of numerical values of its reliability indicators. Ground-based experimental testing of samples of on-board radio-electronic facilities, devices, assemblies and units facilitates the solution of this problem. In the course of this testing, various tests conducted. It been shown that the timeliest information about the quality and reliability of the equipment can be obtained from autonomous tests. In the article, the choice of an autonomous test facility has made. A microprocessor-based temperature controller chosen as an autonomous test object. The expert evaluation method used to select the object. Analysis of specifications carried out. The scope of autonomous tests was determined. An algorithm for autonomous testing of on-board radio electronic equipment of spacecraft was developed. It has properties of discreteness, determinacy, limb and mass. The development of the autonomous test algorithm takes more account of the specifics of the technology used to manufacture the product under test and the test sequence. One of the options for mathematical modelling of the process of selecting test equipment for autonomous tests been considered.

Physics of Wave Processes and Radio Systems. 2020;23(3):97-104
pages 97-104 views

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