Analysis of tunable THz antennas integrated with polarization insensitive frequency selective surfaces

In this article, two different types of polarization-insensitive frequency selective surfaces (FSS) have been employed for integration with the tunable graphene loaded terahertz (THz) patch antennas. Two different types of graphene loaded antennas have been proposed and studied through numerical simulations. The proposed antennas provide the reconfigurable operation. The characteristics of the proposed FSS unit cells are studied and verified with the help of equivalent circuit models. Reflective and transmissive metasurface having band-reject and band-pass filtering characteristics at the operating frequencies of the antenna, have been meticulously placed below and above the tunable antennas, respectively for gain enhancement. The theoretical studies have been validated by numerical simulations.