Terahertz Fabry-Perot Cavity Leaky-wave Antennas

In this work we examine the recent efforts made in the design of either efficient or reconfigurable Fabry-Perot cavity leaky-wave antennas (FPC-LWAs) in the terahertz (THz) range. We start by discussing the radiating performance of an FPC-LWA consisting of a grounded dielectric slab (GDS) covered with a periodic arrangement of fishnet-like unit cells. This antenna design shows a rather high directivity at broadside, but is not capable of reshaping the pattern at fixed frequency. To this purpose, an FPC-LWA, where the periodic arrangement of fishnet-like unit cell is replaced by a uniform (i.e., non-patterned) graphene sheet, is considered to exploit the tunable properties of graphene. The performance of a graphene-based FPC-LWA is analyzed and improved by covering the structure with a high-permittivity material and slightly changing the position of graphene within the substrate. The radiating properties of all the THz structures proposed in this work are evaluated through fully-analytical techniques and validated through numerical results and full-wave simulations.