Multibeam Pattern Synthesis via a Common Subarray Structure Without Reference Information

The multibeam pattern synthesis problem, that is, the primary beam pattern (BP) and the secondary BP synthesis problem, via nonoverlapped subarray, is discussed in this article. The primary BP is synthesized at the element level, while the secondary BPs are synthesized at the subarray level with a common subarray structure. Different from current works optimizing the array excitation with the reference BP or the reference excitation, the article proposes a novel algorithm for multibeam pattern synthesis via a common subarray structure (MBPS-CSS) that does not require any reference information. The proposed MBPS-CSS constructs a nonconvex multibeam synthesis model and recasts it into several simplified subproblems. Based on the penalty dual-decomposition (PDD) framework, the original problem is solved by iteratively solving these subproblems. In such a way, the MBPS-CSS achieves the potentiality to further suppress the sidelobe level (SLL) of the synthesized BPs. Numerical examples for both linear arrays and planar arrays are provided to validate the effectiveness of the MBPS-CSS by comparing it with the existing algorithms.