A Dual-Band Frequency Selective Surface with Angular Stability at X-band

This paper proposes a dual-band frequency selective surface (FSS) design. To achieve dual-band functionality, two similarly shaped elements with different sizes are staggered on the substrate. The filtering response is created through strategically designed slots on the middle layer. Three different FSS configurations are designed and analyzed. The inclusion of arms and stubs enhances isolation between the staggered elements, reducing magnetic coupling and strengthening electric coupling, which improves angular stability. The proposed design shows transmission zeros at 7.75 GHz, 9.6 GHz, and 11.75 GHz, with a suppression level of -20 dB, demonstrating its effectiveness in frequency-selective applications.