A Narrowband Polarization Insensitive Multifunctional Frequency Selective Surface

Abstract

This paper presents a polarization-insensitive frequency selective surface (FSS) switching between different electromagnetic (EM) operations with the help of p-i-n diodes. The proposed unit cell geometry consists of four-fold symmetric metallic patterns etched on two sides of a single FR4 dielectric substrate, and p-i-n diodes are appropriately placed across the design supported with biasing lines. Based on different combinations (ON and OFF states) of top and bottom diodes, four different working states are obtained in the proposed design. When diodes on both top layer (PD1) and bottom layer (PD2) are in the OFF state, the geometry exhibits a transmission response with an insertion loss of 1.8 dB at 5.43 GHz. In the OFF (PD1)-ON (PD2) state, the FSS works as an absorber with an absorptivity of 91.39% resonating at 5.59 GHz. In the same way, the proposed configuration provides a complete reflection for the entire frequency range under the ON-ON state. The detailed methodology of achieving multiple characteristics (absorption, transmission, and reflection) under different polarization angles has been clearly explained and provided with various applications in the practical scenarios. © 2024 IEEE.