Ricerc@Sapienza

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.

Metamaterials have provided applications in spectral ranges covering radio frequencies and ultraviolet. However, most applications have been extrapolated to the visible or near-infrared after being developed at the GHz level. This is due to technological reasons since fabrication of microwave antennas is not as demanding as THz resonators or plasmonic nanostructures. Accordingly, this book has been divided into three parts. In the first part, fundamentals of metamaterials and metadevices are discussed, while describing recent advances in the field.

In this work, a design flow for leaky-wave antennas based on metasurfaces is proposed. In particular, the possibility to extract the surface impedance of partially reflecting surfaces (PRS) for which homogenization formulas are not yet available in the literature has been exploited by means of numerical tools. The knowledge of the surface impedance in a PRS-based Fabry-Perot cavity leaky-wave antenna (FPC-LWA) allows for accurately evaluating the radiating performance by means of simple analytical formulas.