Two-Dimensional Multi-Ring Dielectric Lens Antenna to Radiate Fan-Shaped Multi-Beams With Optimum Adjacent-Beam Overlapping Crossover by Genetic Algorithm

A two-dimensional (2-D) discrete dielectric lens antenna is designed to radiate fan-shaped multi-beam patterns for gain stability in beam switching. The target is to minimize adjacent-beam overlapping transition regions and provide sufficient and similar gains for all field angles when the antenna is employed in a mobile device. This design starts with a conventional 2-D Luneburg lens antenna, and distorts its dielectric permittivity and the sizes of discrete dielectric rings to defocus the pencil beam patterns into shaped ones with a relatively flat pattern for uniform field distribution. The design is realistically implemented at 38 GHz with both simulation and measurement results shown to validate the concept. Successful validation of feasibility in beam synthesis is achieved. Fabrication discrepancy to result in slight radiation degradation is also discussed.