An Etched Planar Metasurface Half Maxwell Fish-Eye Lens Antenna

In this communication, a half Maxwell fish-eye (HMFE) lens antenna is designed in the 8-11 GHz band using etched planar metamaterials composed of an array of nonresonant square rings with gap (SRG). The refractive index of the HMFE lens can be flexibly obtained in two different ways: one is to adjust the edge length of the SRG unit cell; the other is to change the gap size and the line width of the SRG unit cell simultaneously. The HMFE lens fed by a nondirective monopole antenna is embedded in a staircase parallel-plate transverse electromagnetic (TEM) waveguide. A prototype of the lens antenna has been fabricated. Simulation and measurement results of both near- and far-field plots demonstrate good focusing properties of the proposed HMFE lens antenna.