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.

主权项

1. A method of resolving grating lobe detection comprising:
by a controller,
sampling output indicative of signal return from a target from each of a plurality of antenna elements,combining the output from a first subset of the antenna elements selected to form a first aperture to define a first composite signal return from the target for the first aperture,combining the output from a second subset of the antenna elements selected to form a second aperture to define a second composite signal return from the target for the second aperture,processing the outputs defining the first and second composite signal returns to identify a differential phase angle between the first and second composite signal returns,defining an angle of arrival for the target based on the differential phase angle and a phase center offset between the apertures, andoutputting an in-path indicator in response to the angle of arrival being less than a threshold angle for a given range to the target.