A Dual-Polarized Patch Antenna With Electric and Magnetic Coupling Feed for 5G Base Stations

In this paper, a novel design method for dual-polarized patch antennas is presented for base station applications. The proposed antenna is a low-cost design with a simple configuration, which avoids using the conventional high-cost multilayer PCB technology. The antenna is composed of four intersected loop resonators, which are connected to each other at the center. By using the electric and magnetic coupling from the intersected loop resonators, two orthogonal radiating modes are excited from the top radiating patch. With the differential feed on the intersected loop resonators, high port isolation and low cross-polarization level are obtained. Compared to the traditionally designed capacitively coupled antenna, two times wider impedance bandwidth is obtained for the proposed antenna with high isolation (>45.5 dB) and low cross polarization level (< −28 dB). The employed antenna are bend upward to maintain a small aperture size, so that the realized element still fits in traditional base station antenna (BSA) array. The antenna is matched across the band from 1.7 to 3.7 GHz, which can cover both the LTE band from 1.7 to 2.7 GHz and the 5G (sub-6 GHz) band from 3.3 to 3.6 GHz simultaneously.