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

Authors: EMRE ALP MİRAN, MEHMET ÇİYDEM

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$^{\circ}$ 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 $<$$-$25 dB in desired operating band. Antenna exhibits stable, broadside radiation patterns with half power beam-widths of 59$^{\circ}$--64$^{\circ}$ and 69$^{\circ}$--72$^{\circ}$ 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.

Keywords: Dual-polarization, slot coupling, isolation, low profile, broadband patch antenna, sub-6 GHz, 5G, base station antenna

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