A 3-bit Intelligent Reflective Surface with Reconfigurable Phase States, Polarization Insensitivity and Angular Stability for Wi-Fi and IoT applications

This article involves the design and analysis of a novel unit cell designed for Reconfigurable Intelligent Surfaces(RIS) based on metasurfaces operating at 5.8GHz for Wi-Fi and IoT applications. The unit cell consists of a circular loop antenna-inspired structure printed on top of a 1.58mm Taconic TLY substrate which is ground plane-backed. A biasing grid is placed around the loop and a center via is placed connecting the ground plane to the top of the structure. The inner circular loop is designed in such a way as to have more reflection from the surface. The EM simulation of the metasurface is performed and the results are presented in which the 8 distinct phase states with average reflection loss of 1.67 dB are clear. The proposed design is found to be polarization insensitive concerning linear polarization. Also, the angular stability of the structure is tested and works well with fair results till 40°incident angles. The periodicity used here is 25mm. The results are pleasant looking and found to be suitable for Wi-Fi and IoT applications that use the 5.8 GHz - ISM band of frequencies.