Dual‐Function Wideband Geometric‐Phase Metasurface for Simultaneous Reflection and Transmission

Abstract In this work, a compact and wideband metasurface capable of simultaneously performing both reflection and transmission functionalities is proposed. The design integrates an outer double‐split ring resonator (D‐SRR), a ground plane with a connected hollow ring, and an inner X‐shaped resonator. The combination of the D‐SRR and the hollow ring in the ground plane facilitates a wideband reflection response ranging from 6.8 to 15.7 GHz. Simultaneously, the inner X‐shaped structure enables transmission at a distinct frequency of 21.2 GHz. Independent and full‐range phase control is achieved through geometric rotations, maintaining stable amplitude responses across the operating bands. A prototype metasurface is fabricated and experimentally validated for generating vortex and focused beams, demonstrating its versatile performance.