Analysis of multiband graphene-based terahertz square-ring fractal antenna

. A new terahertz square-ring patch antenna is designed basing on a very thin layer of graphene as a radiating patch. It is characterized by multiband operation and can improve the radiation pattern due to its self-similar property or fractal geometry. We analyze a graphene-based square-ring patch placed upon a silicon substrate with the thickness 3.25 µm. The structure has compact dimensions and radiates at a single frequency, 3.62 THz. Our antenna can also consist of a microstrip line to resonate at two (1.913 and 4.294 THz) or three (1.913, 3.167 and 4.260 THz) frequencies. This is achieved by varying the patch shape at the voltage standing-wave ratio less or equal to two. Our calculations are performed using a full-wave electromagnetic simulation based on a standard finite-difference time domain method. Various parameters like the return loss, the voltage standing-wave ratio, the gain and the efficiency are determined for the multiband operation regime.