A Ka-Band High-Gain Dual-Polarized Microstrip Antenna Array for 5G Application

Abstract

A Ka-band high-gain dual-polarized microstrip antenna for 5G application is presented in this paper. The antenna is designed based on the multi-layer printed circuit board technology, which is cost effective and suitable for mass production. In order to improve the bandwidth and realized gain of the antenna array, a microstrip patch antenna with parasitic patches are designed. Each antenna element is fed by two orthogonal microstrip lines to realize both vertical and horizontal polarizations. The vertical polarization is fed directly by microstrip line, and the horizontal one is fed by coupling slot right below the patch. Besides, a crossover slot is cut in the parasitic patch to improve the isolation of cross polarization. An $8\times 8$ antenna array is designed with dual polarization. The feeding networks for the array are designed in different layers to improve the port isolation. A simulated bandwidth from 26.1 to 30.4 GHz ( $\text{VSWR} \leqslant 2$ ), and a peak realized gain up to 21.35 dBi are achieved for both polarizations. The port isolation is over 26 dB, and the cross polarization is below −25 dB. This antenna is a good candidate for 5G communication systems.