Design of A Millimeter-Wave Cylindrical Luneberg Lens Antenna with Multiple Fan-Beams

This paper presents a cylindrical luneberg lens antenna with multiple fan-beams at millimeter-wave frequencies. The cylindrical luneberg lens consists of two parallel metal plates, and five layers of dielectrics are filled between the two parallel plates. The thickness and relative permittivity of each layer is optimized. A novel structure consists of several sheet metals is inserted at the edge of the radiation aperture to expand antenna's beamwidth in vertical plane. The lens is fed by an open ridged waveguide. A waveguide to microstrip transition structure is designed. Finally, an optimized cylindrical luneberg lens antenna is obtained with 18.8 lambda diameter and 0.315 lambda dielectric height, achieves 15.5dBi simulated gain, 8.5 degrees and 104 degrees half-power beamwidth for horizontal plane and vertical plane at center frequency in the V-band, showing a good antenna performance.