PT-Symmetric Metasurfaces and Their Beamshaping and Beamfomring Applications

Antennas with directive radiation have been studied for decades because of their widespread applications in radar, communication, and imaging. Leaky-wave antennas exploiting (fast) leaky wave to form a directive radiation pattern are generally based on passive waveguides and transmission lines with periodically arranged small apertures [1]–[5]. Very recently, leaky waves excited in metamaterial structures, such as the ε-near-zero (ENZ) artificial medium, have been proposed to make compact antennas with enhanced frequency agility and directivity [5]. However, there are still several limitations associated with the fabrication complexity of bulky metamaterials and the resonant absorption in the ENZ band.