Design of a Single-Layer Ultrawideband Cross-Polarization Conversion Metasurface With High Efficiency

In this letter, we present a metasurface for polarization conversion utilizing a quadruple L-shaped structure, and only has a single layer. The metasurface achieves an ultrawide bandwidth, spanning from 5.69 GHz to 14.82 GHz, while maintaining a high polarization conversion efficiency exceeding 90%. The extensive bandwidth can be attributed to the generation of multiple resonances within the quadruple L-shaped unit cell. Surface current distributions are further analyzed to reveal to physical mechanism governing the wide bandwidth in the design. Furthermore, the designed structure exhibits robust performance under oblique incidence, and the average polarization conversion efficiency persists at 80%, even when the incident angle extends to 40(degrees). As a validation, a prototype is manufactured, measured, and the experimental findings demonstrate a satisfactory alignment with the simulated outcomes. Compared with previous designed polarization conversion metasurfaces, due to its simplicity in fabrication and no-manual-assembly design features, the proposed metasurface will be more suitable for practical wideband polarization conversion applications.