A Design of 2-D Wide-Angle Scanning GRIN Lens Antenna with Flat Focal Surface

In this paper, a design method of two-dimensional (2-D) wide-angle beam scanning gradient index lens antenna is proposed. The proposed lens is based on partial maxwell fish-eye lens with a plat focal surface. 2-D wide-angle beam steering is realized by moving the feed on the focal plane. And the edge part in the vertical direction is cut off to improve aperture efficiency. A demonstration of the proposed lens at 10 GHz fed by the circular waveguide is provided in this work. The simulated result shows a 2-D beam scanning range covers pitch angle of 0°-51° with a scan loss of 2.3 dB. The peak gain is 21.8 dBi and the maximum aperture efficiency reaches 51.2%. The sidelobe levels is below -12.6dB within the entire scanning range for both E-plane and H-plane.