A 2-Bit Ku-Band Digital Metasurface with 2-D Scalable Capability

In this letter, the design and implementation of a 2-bit digital metasurface operating in the Ku band are presented, which is engineered to exhibit advanced polarization conversion characteristics. To overcome the scalability limitations in conventional 2-bit metasurfaces caused by dense control routing, a novel radio frequency (RF)-direct current (DC) separation architecture is proposed. In this architecture, the metasurface and the DC control circuitry are integrated onto separate printed circuit boards and interconnected through pin cascading, enabling theoretically unlimited 2-D array expansion. To validate the proposed design, a 32 × 32 metasurface prototype is fabricated and experimentally characterized. The measured results demonstrate that a peak gain of 29.2 dBi and an aperture efficiency of 26.46% can be achieved, confirming both the scalability and performance of the proposed architecture. The developed 2-bit high-gain metasurface provides significant reference value for long-distance communication and radar detection applications. Moreover, the RF-DC separation architecture establishes a pioneering framework for large-scale metasurface deployment in practical engineering scenarios, offering enhanced design flexibility and scalability.