Negative refractive index-shaped lens antenna with straight line condition for wide angle beam scanning

Abstract

For a base station antenna in 5G mobile communications, lens antennas have been proposed for excellent multiple beam performances. In this paper, the negative refractive index (NRI) lens is selected for thinning the lens thickness. By applying lens shaping method, straight-line condition lens is designed. Multi beam radiation characteristics are compared with the conventional hyperbolic shape lens and Abbe's sine condition lens. In order to determine the feed positions for multi beam performances, the focal region ray tracing is performed. The best feed positions are obtained. For calculating multi beam radiation characteristics, ANSYS HFSS software is employed. Multi beam radiation patterns in the wide angle scanning up to 45° are obtained. The results show that the proposed straight-line condition lens achieves higher gain and lower sidelobe level compared to the other two structures. The usefulness of the proposed lens antenna is ensured.