Efficient Directivity Maximization of Time-Modulated Arrays With Two-Stage Convex Optimization

Abstract

An efficient pattern synthesis approach for time-modulated arrays (TMA) is proposed. The method is intended to maximize the directivity of TMA with sidelobe level as constraint. By applying appropriate transformations/approximations, the synthesis problem can be decomposed into two stages with each stage composed by a sequence of convex subproblems, which can be efficiently solved by convex optimization in an iterative manner. In the first stage, the pattern shape at center frequency is optimized to obtain maximized pattern directivity. In the second stage, based on the optimized result in the first stage, the sideband radiation is further suppressed to obtain maximized TMA directivity. The proposed method is capable to solve pencil-beam, wide-beam, and shaped-beam TMA synthesis problems with arbitrary array geometry. Numerical examples are presented to show the robustness of the proposed method.