A Dual-Polarized 3D Frequency Selective Surface at Large Incident Angles

Unlike traditional two-dimensional frequency selective surfaces, three-dimensional frequency selective surfaces achieves wider bandwidth and greater stability under high-angle incidence. This paper presents a dual-polarized 3D-FSS designed for the low millimeter-wave band, optimized for large incident angles. The structure consists of an outer dielectric layer embedding rhombic and multi-bent metallic rings, utilizing its 3D configuration to enhance angular performance. Simulations show that for incident angles of 50°–70°, the shared bandwidth, based on a 1 dB insertion loss, is about 23.7 GHz, with a relative bandwidth of 59%. When the incident angle increases to 70°–75°, the shared bandwidth, based on a 2 dB insertion loss, reaches 25.2 GHz, with a relative bandwidth of 61%. These results indicate potential applications in electromagnetic stealth, satellite communications, and space communication.