Digital Beamforming and Jammer Nulling Method for Wideband Phased Array Radar
宽带相控阵雷达数字波束形成及干扰置零方法

Analog Time Delay Units(TDUs)are usually used for wideband phased array beamforming,but quatilization error and high cost restrict its applications.This paper presents a new wideband digital beamforming method using subarrays and Linear Frequency Modulation(LFM)signal.The algorithm implements stretch processing and narrowband filtering,and achieves digital beamforming by weighting inter-subarrays.Lowpass filtering limits the bandwidth of signal prior to digitization and signal processing,reducing the required speed of subsequent digitization and the computing burden.Furthermore,the presence of wideband interference will degrade performance of one dimension profile.In order to suppress the wideband interference,a new wideband jammer nulling algorithm is proposed based on digital beamforming above.The methods can work well in the case of strong interferences.Finally,influences of distance error and grating-lobe are analyzed and computer simulations demonstrate the effectiveness of the proposed method.