Real-Time Digital Equalization to Enhance Element-Level Digital Beamforming

As the prevalence of digital control at the subarray and element levels increases, radars can leverage techniques such as adaptive digital beamforming (ADBF) to improve data quality at the cost of some computation. For these ADBF algorithms to be effective, precise steering is needed, which itself requires that the channels be well matched. While calibration can be used to improve channel matching, the temperature dependence of the frequency responses of some components means that, even with calibration, the channel mismatch may be higher than desired. Digital equalization was employed on real data suffering from channel mismatch and was able to greatly improve the quality of the channel matching, yielding more accurate beamforming, higher effective bandwidth, and thus higher quality results.