Algorithm for evaluating the directional characteristics of an antenna array with electric scanning in the observation coordinate system

Abstract

An algorithm is proposed for estimating the parameters of the antenna array radiation pattern with electric scanning in the observation coordinate system associated with the phasing direction of the antenna elements. It is shown that in this coordinate system, the concentration of coordinate lines near the phasing direction is maximal. This allows for a relatively small number of observation points to study in detail the parameters of the main beam and the first side lobes of the antenna array, as well as to evaluate the coefficient directivity. The simplest quadrature formula is acceptable for calculating the coefficient directivity in the selected observation coordinate system. The relations for calculating the antenna array radiation pattern taking into account the direction of the beam departures are given. It is shown that taking into account the directivity of individual elements during scanning leads to beam departures, which are convenient to track in the observation coordinate system. Procedures are proposed for estimating the beam width based on linear interpolation of sections of the radiation pattern where the level -3dB intersects. A procedure for estimating the level of side lobes is proposed, which does not include a procedure for searching the area of side lobes. The relations that establish the relationship between the observation coordinate system and the coordinate systems used in radar are given. The results of numerical studies that demonstrate the possibility of visualizing the radiation pattern and its cross-sections in the local coordinate system of the radar system, in the antenna coordinate system, and in the observation coordinate system are presented. This article is the first in a line of research in terms of determining the scientific and methodological apparatus for constructing adaptive algorithms for the diagram-forming scheme of the digital antenna array of radar stations and helps to determine the potential achievable characteristics of newly developed radar stations.