Algorithm for forming a fan of identical beams in digital antenna arrays

Abstract

Digital antenna arrays allow you to implement multipath reception using a grid or a fan of beams. For multiple beams forming the linear phasing method is usually used. The disadvantage of this method is that the directional characteristics of each fan beam depend on the orientation direction of the maximum of the radiation pattern. When the beam deviates from the direction of the normal to the aperture, the following effects occur: expansion of the beam, a decrease in the directivity coefficient and a decrease in the norm of the radiation pattern. This feature of antennas in radar leads to a decrease in the accuracy of measurements of the angular coordinates of targets during electronic scanning. In this regard, it seems urgent to develop new methods and algorithms that ensure the formation of a grid of beams of a digital antenna array consisting of beams with the same directional characteristics. The goal of the article is to form a fan of identical receiving beams of a digital antenna array in a given angular sector. The problem of constructing a fan of beams in a given angular sector with close values of the directivity coefficient and the same beam width has been solved. The proposed algorithms increase the speed of spatial viewing by 20–25%, stabilize the level of the intersection of the beams in the entire sector of electronic scanning and reduce the side lobe level by 23 dB in the central part of the beam grid and by 5 dB for the extreme beams.