Design of a Graphene-Based Hexagonal Circular Patch Yagi-Uda MIMO Antenna

The purpose of this study is to build a Terahertz (THz)-based 2×2 multi-input, multi-output (MIMO) hexagonal angular patch (HCP) antenna. Graphene's unique electrical properties have made it a compelling material for THz-frequency antennas, owing to its capacity to support surface plasmon polariton (SPPs) and high conductivity in this range. We've constructed the antenna on a silicon nitride (Si3N4) substrate, 17 microns thick, with 0.1-micron-thick graphene layers to enhance MIMO antenna efficiency and directivity. The hexagonal patch structure of graphene was chosen for its exceptional characteristics at Terahertz frequencies. Our study highlights the radiation properties of THz-based HCP antennas across the 0.1 THz to 1 THz frequency range. Notably, we achieved return loss (S11) better than -10 dB at 0.52 THz for the unit cell and for the MIMO antenna at 0.69 THz, more bandwidth was achieved. Both the radiation patterns and S-parameters exhibit significantly improved gain and directivity compared to traditional antennas.