An Optimal Baseband Delay-Based Beam Squint Removal Scheme across a Range of Steering Angles for Digital Wideband Beamformers in Radars

Abstract

This paper is an attempt to mitigate the beam squint happening due to frequency-dependent phase shifts in the wideband beamforming scenario, specifically in radar applications. The estimation of the direction of arrival is significant for precise target detection in radars. The undesirable beam squint effect due to the phase shift-only mechanism in conventional phased array systems, which becomes exacerbated when dealing with wide bandwidth signals, is analyzed for a large set of steering angles in this paper. An optimum baseband delay combined with the phase shift technique is proposed for wideband radar beamforming to mitigate beam squint effectively. This technique has been demonstrated to function properly with 1-GHz carrier frequency for signals with wide bandwidths of up to +/-250MHz and for steering angles ranging from 0 to 90 degrees.