宽带相控阵雷达数字波束形成及干扰置零方法

Digital Beamforming and Jammer Nulling Method for Wideband Phased Array Radar

宽带相控阵波束形成通常使用模拟延时线,但量化误差及硬件的高代价阻碍了它的应用。该文在基于子阵和发射为线性调频信号的前提下,提出一种宽带子阵数字波束形成方法。该方法首先对接收信号拉伸处理和低通滤波,然后在子阵间加权实现宽带子阵数字波束形成。低通滤波后的数字采样和信号处理均可在低的速率下进行,大大降低了运算量且容易实现。此外,宽带干扰的存在会严重影响一维距离像的性能,为了抑制宽带强干扰信号,在上述数字波束形成的基础上,提出了一种宽带干扰置零方法。该方法在强宽带干扰功率的情况下仍可很好地工作。最后,对测距误差和子阵栅瓣的影响进行分析并仿真证实了该方法的有效性。

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 beaanforming method using subarrays and Linear Frequency Modulation （LFM） signal. The algorithm implements stretch processing and narrowband filtering, and achieves digital beaanforming 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.