Phase Cancellation-Assisted BGWO Method for Advanced Design of Ultrawideband RCS Reduction Metasurface

A phase cancellation-assisted binary gray wolf optimization (BGWO) algorithm is proposed in this article to create an advanced design methodology for ultrawideband radar cross-section (RCS) reduction metasurface. By embedding phase-difference constraints into the initialization stage and incorporating fitness-guided refinement, the method enables rapid generation of AMC configurations with enhanced efficiency, accuracy, and adaptability to diverse metasurface architectures. Characteristic mode theory (CMT) is employed to validate the phase cancellation mechanism, enabling quantitative validation of current cancellation mechanisms and revealing the modal contributions that drive broadband RCS reduction. As a demonstration, a triangular checkerboard (TCB) metasurface is designed, enabling broader angular diffusion and effective multidirectional RCS reduction. With a unit cell periodicity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.176\lambda _{L}$</tex-math> </inline-formula> and a thickness of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.08\lambda _{L}$</tex-math> </inline-formula>, the design satisfies the electrically small condition, favoring angularly stable and low-profile implementation. It features a 10 dB RCS reduction over a 94% fractional bandwidth (4.4–12.2GHz) and exhibits polarization insensitivity and maintains angular stability up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${40}^{\text {o}}$</tex-math> </inline-formula> for both linear polarization (LP) and circular polarization (CP). Simulation and experimental results confirm the efficacy of the proposed method, underscoring its potential for advancing stealth material development.