A Compact Dual-Polarized Frequency-Selective Metasurface Enabling Independent Functionalities With Reduced Backward-Scattering

A novel dual-polarized dual-functional frequency-selective metasurface (FSMS) with low backscattering characteristics is proposed by combining the polarization converter with a bandpass frequency-selective surface (BP-FSS). The FSMS structure consists of diagonally aligned metallic strip gratings (MSGs) on two substrate layers, and provides two independently tunable functionalities, including wideband reflective cross-polarization conversion (RCPC) in the C-band with a simulated polarization conversion ratio (PCR) exceeding 99%, and co-polarized bandpass transmission in the S-band with insertion loss less than −1 dB. The design concept is validated using an equivalent circuit model (ECM) cascading polarization converter and BP-FSS, as well as measurement of the fabricated prototype. Both the ECM predictions and measurements are in good agreement with the full-wave electromagnetic (EM) simulation. Besides, when the proposed structure is arranged in a chessboard configuration, the low backscattering reduction is achieved only within the RCPC range. Unlike previously reported dual-functional MSs, the proposed FSMS eliminates the need for an additional BP-FSS layer and a complete ground plane for the RCPC response. Owing to compactness and independent tunable functionalities, the proposed FSMS is well-suited for antennas, radomes, and communication applications.