An Efficient Approach for the Synthesis of Large-Scale and Ultra-Wideband Sparse Circular Planar Arrays

Optimizing the layout for large-scale and ultra-wideband arrays to reduce the peak sidelobe level (PSLL) under multiple constraints is a challenging task. This paper proposes an efficient and fast synthesis method for large-scale ultra-wideband sparse circular aperture arrays (LUSCA). In the proposed method, the array aperture is divided into several rotationally symmetric sectors to reduce the number of unknowns in both the array layout and the computation process. Then, a new element filling strategy is introduced. This strategy is able to sequentially place independent elements into the sectors while ensuring that each new element satisfies the minimum spacing constraint based on the existing element positions. This approach ensures that the array layout in each sector meets multiple constraints, thus avoiding invalid solutions during optimization. In addition, the reduced optimization region and the new element filling strategy enable the fast synthesis of the array's radiation pattern. A series of numerical examples demonstrate the effectiveness and robustness of the proposed method. Compared with existing state-of-the-art methods for synthesizing LUSCA, the proposed method can achieve much lower PSLL and significantly reduce computation time.