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

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 degrees 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 vertical bar S-11 vertical bar, vertical bar S-22 < - 15 dB, covering the 5G spectra of 3.30-3.80 GHz. The isolation between ports (vertical bar S-21 vertical bar) is obtained as < - 25 dB in desired operating band. Antenna exhibits stable, broadside radiation patterns with half power beam-widths of 59 degrees-64 degrees and 69 degrees-72 degrees. 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.