This paper presents a novel 1-bit phase shifter for reconfigurable intelligent surfaces (RIS) operating across 2:1 bandwidth with minimum phase errors. The proposed RIS consist of 3 layers as follows: 1) reflective periodic surface with PIN diodes to route the signals to the 1-bit phase shifter, 2) the 1-bit phase shifter middle layer comprised of two different paths using elliptically tapered patch-based couplers (one per path) and 180° phase difference 3) RIS digital backend. The 1-bit phase shifter layer is unique in achieving up to 180°±5° phase control across a wideband 20-40GHz. Leveraging the proposed design, a cost effective and wideband RIS is demonstrated with a 75% phase error improvement as compared to earlier publications.
