DIGITAL BEAMFORMING BASED RESOLUTION OF OUT-OF-PATH TARGETS SHOWING UP AS IN-PATH DUE TO GRATING LOBES IN ARRAY ANTENNA RADARS

摘要

An antenna system, such as a radar antenna system, includes an array of antenna elements and a controller. The controller outputs an in-path indicator in response to an angle of arrival for a target being less than a threshold angle for a given range to the target. The angle of arrival is based on a differential phase angle derived from data defining first and second composite signal returns from the target associated with first and second apertures respectively, and a phase center offset between the apertures. The first and second apertures are formed from first and second subsets of the antenna elements respectively.