A Dual-Band Quad-Polarized Multibeam Shared-Aperture Reflectarray for Wireless Communication

This letter presents a novel dual-band quadpolarization (DBQP) reflectarray (RA) capable of independent beamforming for dual-linear polarization (DLP) in the Ku band and dual-circular polarization (DCP) in the Ka band. The proposed RA unit cell achieves 3 × 3 bit phase encoding for both DCP (Ka-band) and DLP (Ku-band) with a thickness of 0.1 λKu (λKu is the free-space wavelength at 18 GHz). A prototype of RA, configured with four beams, is designed, fabricated, and experimentally validated. The four-beam DBQP RA exhibits peak aperture efficiencies exceeding 40% in the Ka band and 50% in the Ku band, with bandwidths wider than 10% (Ka band) and 20% (Ku band). Specifically, the peak gains and sidelobe levels of the four beams are as follows: 27.6 dBic/-21.7 dB (left-hand circular polarization), 27.8 dBic/-19.2 dB (right-hand circular polarization), 24.6 dBi/-16.2 dB (X-linear polarization), and 24.8 dBi/-20.1 dB (Y-linear polarization), respectively. This high-performance RA demonstrates strong potential for dual-band wireless communication applications.