A Simplified 2-Bit Energy-Efficient Reconfigurable Intelligent Surface Architecture

Abstract

Electronically reconfigurable intelligent surfaces (RIS) offer a power-efficient solution for enhancing coverage, reducing latency, and enabling programmable propagation in emerging 6G wireless systems. This work presents a compact RIS unit-cell operating under circular polarization, formed by integrating four PIN diodes within a circular slot to realize a complementary split-ring resonator. The design achieves high reflection efficiency over 4.42-5.06 GHz (13.5% bandwidth) while providing 2-bit discrete phase control through diode state switching. The proposed approach enables low-loss, wideband, and fast reconfigurable beamforming suitable for scalable RIS deployments.