Dual-polarized elliptic-H slot-coupled patch antenna for 5G applications

Abstract

A dual-polarized, slot-coupled dielectric patch antenna design is presented in sub-6 GHz for 5G base stations. Proposed antenna is implemented using two dielectric patch layers (main patch and parasitic patch) above a feeding line layer. Excitation is realized by crossed elliptic-H slots in order to create orthogonal ± 45◦ polarizations. Through the use of patches at proper heights together with elliptic-H slots, significant improvement in impedance bandwidth, matching level, isolation and front-to-back ratio is acquired. Prototype antenna has an impedance bandwidth of 18.5% (3.23–3.85 GHz) for $|S_{11}|, |S_{22}|$ < −15 dB, covering the 5G spectra of 3.30–3.80 GHz. The isolation between ports $( |S_{21}| )$ is obtained as < −25 dB in desired operating band. Antenna exhibits stable, broadside radiation patterns with half power beam-widths of 59 ◦ –64 ◦ and 69 ◦ –72 ◦ in E/H-planes, respectively. Gain of the antenna varies within the range of 7.9–8.4 dBi. Proposed antenna is also low profile (9.8 mm). It needs no reflector or cavity-backed structure and meets all the requirements of 5G base stations as an antenna element. Design details, numerical studies, and experimental results are presented.