A 3-D-Printed Multibeam Spherical Lens Antenna With Ultrawide-Angle Coverage

A 3-D printed multibeam spherical lens antenna with 2-D ultrawide-angle coverage is presented in this letter. The two-layer spherical dielectric lens can be fabricated easily by 3-D printing technology based on the effective medium theory. The circularly polarized U-slot patch antenna is introduced as the feed for the spherical lens due to its good radiation performance and compact configuration. The 2-D beam scanning can be achieved by switching the multiple feed elements, which are positioned around the spherical lens. Experimental results indicate that the -10 dB impedance and the 3 dB axial ratio (AR) bandwidth is over 7.7to 8.2 GHz, and the isolation between the adjacent feeds is higher than 20 dB. The 46 stable radiating beams are able to achieve a beam coverage of 360° of in the azimuth plane and almost 90° in the elevation plane.