Review of Highly-Directive Flat-Plate Antenna Technology with Metasurfaces and Metamaterials

A review of the development of enhanced directivity applied to high gain antennas is shown here, illustrating the various design possibilities. Fabry-Perot cavities (FPC) covered by partially reflective surfaces (PRS) made by high density dielectric layers or frequency selective surfaces is the standard way to obtain such antennas. Ground planes may be substituted by artificial magnetic surfaces to reduce the overall thickness, metamaterials with low permittivity have been used to generate highly directive beams as well. In all cases high directivity is produced by the excitation of low attenuating leaky waves in the antenna transverse direction