A Low-Profile Hybrid-Fed Dual-Polarized Antenna with High Isolation and High Cross-Polar Discrimination

Abstract

─ This work presents a wideband hybrid-fed ±45o linear dual-polarized patch antenna design for sub6 GHz 5G base stations. Two polarizations are created by a slot-coupling with rectangular H-slot (+45) and a capacitive coupling with modified L-probe (−45). Antenna exhibits wideband −10 dB impedance bandwidths of 40.7% and 35.6% for slot-fed and probe-fed ports, respectively. Due to the special design of suspended stacked patches with hybrid-fed excitations, high port isolation (< −47 dB) and high cross-polar discrimination (> 38 dB) are achieved. Symmetric and directional radiation patterns with stable gain are obtained in E and H planes for each polarization. Compared to its bandwidth, antenna is low-profile (10.6 mm) with front-to-back ratio greater than 22 dB. Simulations and experimental results are reported and discussed. Index Terms ─ 5G base station, cross-polar discrimination, dual-polarization, hybrid feeds, isolation, low-profile, massive MIMO, sub-6 GHz, wideband patch antenna.