Optimal Radiation Pattern of Feed of Luneburg Lens for High-Gain Application

Abstract

The focus of this communication is to study about the optimal radiation pattern of the feed of Luneburg lens for high-gain application. Based on geometric optics and equivalent aperture theory, the effect of the radiation pattern of the feed on the gain of Luneburg lens is analyzed first. Then the optimal radiation pattern of the feed is predicted by theoretical calculation to guarantee the maximum radiation gain of Luneburg lens, and the half-power beamwidth (HPBW) of the optimal radiation pattern of the feed is near 68° for the Luneburg lens with a radius greater than three wavelengths. To verify the theory, the Luneburg lens antennas fed by the feeds with different radiation patterns working at 10 GHz are analyzed. Finally, a prototype of Luneburg lens with a radius of 100 mm and several different feed antennas are manufactured to verify the theory and the simulation. The final simulated and measured results are consistent with the theory.