Multibeam Dual-Polarized Shared-Aperture Antenna Array for Micro Base Stations

In this paper, a novel multibeam dual-polarized shared-aperture antenna is proposed for the micro base station. It consists of four cavity-backed monopole antenna elements, two ME-dipole antenna elements, and four tapered slot antenna (TSA) elements. The monopole antenna is loaded with a semi-open reflection cavity, which enhances the bandwidth and transforms the radiation pattern from omnidirectional to directional. To steer the radiation beam toward the boresight direction, two feeding probes are utilized to excite the ME-dipoles formed by the cavity plates. They enhance integration and miniaturization. Meanwhile, four TSAs are strategically placed in the gap between adjacent vertical metal plates to realize the dual-polarized beam coverage in the azimuth plane. The proposed antenna has been fabricated and tested. It achieves a wide impedance bandwidth, covering the 1.7-2.7 GHz 4G Long-Term Evolution band, for all ten ports. Simultaneously, it has achieved an exceptionally wide coverage with dual-polarization, encompassing both the azimuth plane and the boresight direction. The proposed antenna array is particularly attractive for the indoor ceiling micro base station application.