A Wideband Dual-Circularly Polarized Luneburg Lens Multibeam Antenna Feed by Dual-Linearly Polarized ME-Dipole Antennas

This paper presents a wideband dual circularly polarized (CP) Luneburg Lens (LL) multi-beam antenna for 6G or satellite communication applications. The antenna system consists of six ±45° dual linearly polarized (LP) antennas and a 3D printed LL. To simplify the antenna design and avoid the complexity of multi-layer blind vias, a hybrid feeding method combining parallel L-shaped probes and a coupled slot is employed, achieving high port isolation and dual-polarized radiation. The spherical dielectric LL is engineered to function as a dielectric polarization grid, enabling the conversion of LP waves into CP waves, while also focusing electromagnetic energy. By integrating the proposed dual-LP feed antenna with the spherical dielectric LL, a wideband, high-isolation, dual CP multi-beam antenna with extensive coverage was realized. The design was validated through fabrication and measurement of the proposed system. The results demonstrate an overlapped bandwidth of 23% (26.5–33.5 GHz), port-to-port isolation level exceeding 27 dB, and a peak gain of 18.9 dBic, with six beams covering a ±81° scanning range.