Broadband metamaterial-based half Maxwell fish-eye lens antenna

A low-profile substrate-integrated lens antenna is designed using planar metamaterials for a broadband operation. The lens antenna is based on embedding a Vivaldi source inside a parallel-plate waveguide to illuminate a half Maxwell fish-eye (HMFE) lens operating in X-band. The focusing condition of the lens, requiring a gradient refractive index is achieved through the use of complementary non-resonant metamaterial structures. Far-field radiation patterns have been measured on a fabricated prototype in an anechoic chamber. It has been shown that the proposed planar antenna presents good focusing properties.