A. Ludwig, C.D. Sarris and G.V. Eleftheriades

Ludwig and his collaborators designed a metasurface to achieve near-field subwavelength focusing at a given frequency. Interestingly, in the vicinity of this frequency the metasurface acts as superdirective antenna in the farfield. The principle of operation of this discovery is explained and different designs are proposed in both microwave and optical regime. In our group it is very important to understand the operation principles of these devices in order to design the metamaterials that placed close to an antenna, improve its performance. We are using a similar approach to enhance the directivity of Leaky Waveguide Antennas.