Design of graphene-based plasmonic nano-antenna arrays in the presence of mutual coupling

Graphene-based plasmonic nano-antennas are envisioned as an enabling component for compact communication systems in the Terahertz (THz) band (0.1–10 THz). Despite their high efficiency and due to their reduced size, the total radiation power of individual nano-antennas is expectedly very low. To overcome this limitation, plasmonic nano-antenna arrays are proposed. In this paper, the performance of such arrays is analyzed while taking into account mutual coupling effects. First, by utilizing coupled mode theory, the impact of mutual coupling on the nano-antenna response is modeled. Then, the array factor and total gain for nano-antenna arrays is derived. Extensive electromagnetic simulations are conducted to validate the developed models and provide numerical results. It is shown that a nano-array can provide significant gain in relation to only a single nano-antenna while still occupying a compact footprint.