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• ANALYSIS OF THE CAUSES OF ERRORS IN THE AMPLITUDE-PHASE DISTRIBUTION OF LINEAR PHASED ANTENNA ARRAYS AND METHODS FOR THEIR REDUCTION

  S.S. Bybin , N.P. Dunaev , S.V. Kuzmin , А.N. Morozov

  2026-02-27

  Abstract ▼

  To use a phased array antenna in the beamforming mode, it is necessary to establish a certain amplitude-phase distribution at the inputs of the emitting elements. Amplitude and phase errors distort the radiation pattern. The paper analyzes the sources of errors in the amplitude-phase distribution of phased antenna arrays, including parasitic phase shifts, nonlinear amplification paths, temperature instability and mutual electromagnetic coupling between the elements. Three methods of calibration and adjustment of phased antenna arrays are described, based on direct measurements of the transmission coefficients in the near zone and the subsequent calculation of the impact vector using inverse and pseudo-inverse matrices of mutual connections, which provides a systematic approach to error elimination. To obtain the initial values, each channel was pre-calibrated along a closed path using a vector network analyzer. Technique 1 implements correction for a set of points in space and one set of states of each channel. To increase the stability of the solution, method 2 uses the regularization of the elements of the matrix of interconnections based on an additional set of measured states of each channel. Method 3 makes it possible to construct a mathematical model of a specific implementation of a phased array antenna based on measurements with a fixed channel state, which ensures the formation of an arbitrary amplitude-phase state without repeated measurements. An experimental setup of an eight-element equidistant linear phased array antenna was carried out. The lattice attenuator/phase shifter modules are based on the PE44820 phase shifter and PE4302 attenuator debugging boards and are controlled by a microcontroller to automatically change phases and amplitudes. The measurements were carried out automatically on a near-field stand in an anechoic shielded chamber using a vector network analyzer. Calibration results are presented, matrices of mutual relationships are constructed and radiation patterns are formed, confirming the operability of the proposed approaches. Since the experimental array is low-element, the results of applying the considered techniques are compared with the results of tuning in the far zone performed using an evolutionary algorithm.

• REALIZATION OF METHODS FOR SYNCHRONIZATION OF DATA FLOWS IN DIGITAL SIGNAL PROCESSING SYSTEMS

  I.I. Levin , D.S. Buryakov

  119-134

  2025-07-24

  Abstract ▼

  In digital signal processing applications involving coherent processing of data from a phased antenna array, it is important to ensure the coordinated arrival of digitized data from antenna elements to processing units. As the number of data transmission channels in DSP complexes grows, the probability of errors in the data transmission channels increases significantly, which puts forward increased requirements to the assurance of the program complex of isochronous data transmission. The paper presents the results of the development and realization of methods that increase the assurance of isochronous data transmission. A combined method of isochronous data transmission is proposed, characterized by the use of service gaps in the transmission of operand arrays and dynamic compensation of delays in data channels. The most probable errors occurring during data transmission are singled out and methods of their parrying are proposed. A program complex realizing the combined method is described. Using the attributive model of dependability, the dependability of the program complex is analyzed. The analysis has shown that the use of the combined method will quadruple the number of data transmission channels in the DSP complex at a given level of dependability and fixed time of reliable operation in comparison with the basic method. With a significant increase in the number of data channels, there is a need to maintain a given level of dependability. In this regard, a modernized method of isochronous data transmission is proposed, in which the algorithms for checking data integrity, checking the acceptable range of delay mismatch in the data channels and the algorithm for switching the reference channels were improved. An evaluation of the implementation dependability of the modernized method showed its ability to provide twice the number of data channels compared to the combined method.

• ADAPTATION OF INFORMATION AND TECHNICAL CHARACTERISTICS TO THE CONSTANTLY CHANGING PARAMETERS OF IONOSPHERIC PROPAGATION

  A.I. Rybakov, R.E. Krotov, S.A. Kokin

  2020-07-20

  Abstract ▼

  The aim of the research work was to study and select the existing adaptation options for
  transmission parameters, in order to reduce the influence of shortcomings of the short-wave radio
  line, it is advisable to use the methods of digital signal processing as efficiently as possible. According
  to the results of the characteristics of analog-to-digital converters (ADCs), it became a
  study of the available hardware for constructing extended radio links, it was concluded that with
  an increase in the performance of FPGAs on which digital signal processing is implemented, it is
  possible to implement the technology of creating an active antenna array (AAR), consisting of the
  Nth number of independent antenna modules, which is a conceptual task in solving the issue of
  adapting information and technical characteristics to constantly changing parameters of
  ionospheric transmission, for a more energy-efficient approach to designing an ionospheric radio
  communication system. Improving the performance of the radio system by improving communication
  protocols, solving the problem of optimal channel load from the time of formation and reception
  of signals. The main idea of such an AAR is to digitize or generate a high-frequency signal in
  the immediate vicinity of the antenna, as part of the antenna modules. The indicated results make
  it possible to replace separately tuned radios and transceivers built according to a complex superheterodyne
  circuit with a limited number of available hardware units operating under software
  model of a software-configurable radio channel. In the next work, it is planned to conduct studies
  to assess the passage of OFDM signals through multipath communication channels with fading of
  Rayleigh and Rice. The resulting model will allow us to evaluate the noise immunity at different
  lengths of the cyclic prefix of the OFDM symbol and to observe the behavior of the signal constellation
  under the influence of various instabilities.

• DEVELOPMENT OF A FOUR-STAGE LUNEBERG LENS FOR ANTENNA ARRAYS OF RADIO DIRECTORS

  D.E. Gubarev, Y.V. Yukhanov

  2022-01-31

  Abstract ▼

  As part of the research and development work "Lens" carried out at the enterprise JSC
  "TNIIS", a design of a four-stage Luneberg lens was developed on the basis of a homogeneous
  stepped dielectric, a model with an external diameter of 210 mm was made (dielectric material
  PT-3 distribution of rays at the exit of the lens aperture. The width of the BP ranged from 10 -14
  degrees. The level of side lobes at frequencies fw, fav, fn does not exceed -13 dB in level, weight
  0.3 kg. According to these parameters at the given frequencies, the lens differs from previously
  developed analogs. The purpose of the work is to develop a design and manufacture a model of a
  four-stage Luneberg lens based on a homogeneous stepped dielectric, which will not be inferior in
  its characteristics to foreign counterparts, which will provide the possibility of import substitution.
  And also one of the goals of the work is to simplify the coordination of such a lens with a feeder
  path and transceiver equipment, the production of which would be economically feasible in comparison
  with analogs. It is also necessary to conduct an experimental study of the beamforming
  device based on this lens in order to obtain the directional patterns of the central beam and in all
  7 output beams of the Luneberg lens at the given three frequencies.