Homogeneous Dielectric Multi-beam Spherical Lens Antenna with High Crossover Gain for Wide-angle Coverage in the 270-GHz Band

A wide-angle multi-beam spherical dielectric lens antenna suitable for mobile communications in the 300-GHz band is developed. The proposed antenna comprises a spherical lens made of a homogeneous dielectric material, which is easy to fabricate even in the sub-terahertz band, and has multiple horns acting as primary radiators arranged in a circular arc around the spherical lens. By switching the feeding of primary radiators, the spherical lens antenna forms a multi-beam over a wide angular range. By optimizing the placement distance of the primary radiator relative to the spherical lens and the arrangement angle pitch of multiple primary radiators, not only the peak gain of the multi-beam but also the crossover gain between adjacent beams is enhanced. The developed antenna demonstrated a crossover gain higher than 26 dBi within an angle range of ±30° from 250 to 290 GHz, as well as a lens aperture efficiency greater than 50%.