Chessboard-like conformal metastructures enabled by dual complementary mechanisms: Achieving ultra-wideband RCS reduction under large curvatures

Conventional metastructures encounter limitations in simultaneously achieving broadband performance, thin thickness, and adaptability to curved surfaces. To overcome these challenges, a chessboard-like metastructure was developed based on a dual complementary mechanism of electromagnetic (EM) absorption and phase interference, aimed at enhancing its radar cross section (RCS) reduction performance. Through the design of multi-scale unit cells and optimized spatial arrangement, a − 10 dB RCS reduction bandwidth spanning 5.3∼18 GHz was achieved. Notably, the propagation phase compensation model was introduced to ensure stable performance under extreme curvature (α=180°) and wide-angle incidence (0°∼60°), surpassing existing conformal metastructures in bandwidth efficiency. The influence of unit cell parameters on RCS reduction was systematically investigated and validated through simulations and experimental measurements. This work offers a viable approach for the design of lightweight, ultra-thin metastructures with strong potential for conformal EM stealth applications.