An ultra-wide-angle coverage spherical Luneburg lens antenna for high-gain communication base stations

Abstract

An ultra-wide angle coverage multi-beam spherical Luneburg lens antenna is proposed based on the thickness equality principle and the equivalent medium theory, with its gradient relative permittivity realized by “air-dielectric-air-dielectric” nested structure. Working in Sub-6GHz band, the simulated results show a peak gain of 15.8 dBi, the side lobe level of -12dB, and promising radiation patterns with the dual polarization scanning of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm 90^{\circ}$</tex> in the azimuth plane and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm 30^{\circ}$</tex> in the elevation plane, respectively. The overall performance of the prototype lens antenna demonstrates that this lens would be an attractive candidate for the wireless applications and 5G communication base stations.