Grid-Constrained Rotating and Displaced Subarray Design for Large-Spacing Arrays via Iterative Convex Optimization

This paper presents a grid-based design framework for rotated subarray configurations to address the grating lobe (GL) suppression challenge in large-spacing arrays (element spacing ><inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\lambda /2$</tex-math></inline-formula>). The proposed method combines rotational subarray techniques with a constrained grid structure, achieving effective GL suppression while maintaining array modularity and reducing design complexity. By formulating the problem via iterative convex approximation, subarray positions and rotation angles are alternately optimized, achieving greater design freedom than prior methods. Numerical simulations validate the method's superiority over conventional approaches in both GL suppression performance and structural practicality. The optimized design achieves 1–4dB better GL suppression than existing solutions across various array configurations.