A dual‐polarized antenna with low cross polarization, high gain, and isolation for the fifth‐generation array/multiple‐input multiple‐output communications

Abstract

A dual-polarized antenna for the fifth-generation (5G) array/massive multiple-input multiple-output (MIMO) communications is proposed in this paper. Through combining dual-polarized differentially feeding structure and complementary magneto-electric (ME) dipole antenna, low cross polarization (X-pol), high gain, and isolation characteristics can be achieved by the antenna element. To take advantage of these characteristics in the array, a modified 1-to-16-way H-shaped differentially feeding network is designed to feed the 16-element antenna array. Here, vertical cross-shaped patches with dotted slots are arranged between adjacent ME-dipole antenna elements to further improve the array isolation. By removing the H-shaped differentially feeding network and the substrate at the bottom, a high-capacity MIMO antenna system can be achieved. Measured results show that low X-pol level of −35.7 dB and high gain of larger than 8.1 dBi can be attained by the antenna elements across the 5G frequency bands (3.3-5.1 GHz). In addition, the antenna array has exhibited high gain of 17.3 dBi and the MIMO antenna has realized very low envelope correlation coefficient of 0.004.