A Wideband Dual-Polarized Reconfigurable Reflectarray Using Polarization Rotation Technique

This paper presents a wideband dual-polarized 1-bit reconfigurable reflectarray antenna (RRA) at Ku-band, featuring a novel multi-layer unit cell with two substrates and three metallic layers. By utilizing the out-of-phase characteristic of the electric field in the dominant mode of the patch and polarization conversion, the design achieves two distinct phase states with accurate resolution over a wide bandwidth. Two PIN diodes serve as switches, enabling 180° phase difference between states while converting an x-polarized incident wave to a y-polarized reflected wave (and vice versa). A single control signal simultaneously operates both diodes, significantly simplifying the control system. Simulations confirm a 180° ± 2° phase difference from 10 GHz to 15 GHz. To explore beam steering capability, a $10 \times 10$ reconfigurable reflectarray prototype was fabricated and tested, with each unit cell wired to a DC biasing board and controlled via an SPDT manual switch. Measured results demonstrate beam steering up to 50° in both planes for both polarizations, with a 1-dB gain bandwidth of 13.7% (12.2 GHz-14 GHz), closely matching simulations. The combination of wide bandwidth, dual-polarization capability, and simplified fabrication makes this design highly suitable for beam-steering applications.