Study on ADBF Methods at Subarray Level

This paper studies adaptive digital beamforming (ADBF) at the subarray level. We present the signal model, generalize the optimum weights at element level to ones at subarray level directly, get the general form of the conventional weights at subarray level and discuss it based on different criteria. Moreover, by introducing the mismatched vector we improve the optimum weights at subarray level. The improved methods can work not only in the presence of jammers but also in the absence of jammers. The desired quiescent patterns can be obtained without SLL (sidelobe level) losses in the absence of jammers and also the SLL improves remarkably in presence of jammers. Simulation results indicate the validity of the introduced methods