A Novel Cross-Band Decoupled Shared-Aperture Base Station Antenna Array Unit for 5G Mobile Communications

Abstract

In this paper, a novel compact, dual-polarized, dual-broadband shared-aperture antenna array unit consisting of a lower-band (LB) element and 4 upper-band (UB) elements underneath is proposed for 5G mobile communications. L-shaped parasitic branches are introduced in the LB to expand the bandwidth and suppress the mutual coupling between the LB element and UB elements. Compared with the traditional lower-band dipole, the proposed LB element has far less influence on the electric field of the UB array, thus preserving their radiation patterns. To verify the performance, the antenna was fabricated and experimentally demonstrated to achieve the bandwidth of 32.7% (0.69-0.96 GHz) in the LB and 45.5% (1.7-2.7 GHz) in the UB with VSWR < 1.5. High port isolation and stable radiation pattern have been attained in both the LB and UB as required for dual-band base station antennas.