A Multibeam Luneburg Lens Antenna Based on a Dielectric Cone with Hollow Structure

This paper presents a multibeam Luneburg lens antenna in the K/Ka band. The proposed lens is composed of a certain number of dielectric cones on a dielectric sphere. By adjusting the number and internal structure of the cones, it can achieve almost the same graded refractive index as the ideal Luneburg lens and reduce the potential reflection caused by the lens itself concurrently. Eight microstrip antennas are introduced as the feeders. The antenna can realize a dual circular polarized multibeam radiation at 19–20 GHz and 28–29 GHz with high gain, acceptable impedance matching, and low multiport isolation. The simulation results indicate that the proposed antenna has great potential to be applied to satellite communication terminals.