A Printed, Broadband Luneburg Lens Antenna

The design of a 2D broadband, Luneburg lens antenna implemented using printed circuit board techniques is detailed. The refractive index of the lens is controlled through a combination of meandering crossed microstrip lines and varying their widths. The 12.4λ
_°
diameter lens is designed to operate in the transverse electromagnetic (TEM) mode at 13 GHz. The lens antenna was designed, fabricated, and measured. The measured half power beamwidth of the experimental antenna is 4.34°.