Broadband Dual-Polarized Antenna Element for 5G Base Station Using Characteristic Mode Analysis

A broadband dual-polarized antenna element is proposed for the 5G base station antenna application. The behaviors of the proposed antenna are investigated using the characteristic mode analysis. Characteristics mode 1 and 2 share the same resonant frequency, and their current distribution are orthogonal. The third mode, which is independent from the other modes, is utilized to achieve the desired resonant frequency. The dual-polarized antenna has the S11
$\boldsymbol{\leq-10\text{dB}}$
bandwidth spans from 2.45 GHz to 4.1 GHz, and a gain of 8.5 dBi. The port to port isolation is more than 30 dB from 2.5 GHz to 4.1 GHz.