Subtracted Flat Generalized Luneburg Lens for High Gain and Low Profile Applications

A subtracted flat generalized Luneburg lens (GLL) based on the transformation optics theory is proposed for high gain and low profile applications. The flat GLL could be fabricated with discretized isotropic materials using 3D printing technology. To facilitate analysis, a circular polarized microstrip antenna operating at 10GHz is selected as the feed of the lens antenna for verifying the high gain performance. The radiation patterns of the lenses with feed have been simulated. Comparisons of the present design with others, the results show that the gain of the subtracted flat GLL is 12dB higher than that of the single microstrip antenna. Meanwhile, it is worth pointing out that, with their gains almost the same, the profile of the subtracted flat GLL is 71.7% lower than that of the traditional Luneburg lens (TLL), and 15% lower than that of the flat TLL.