A Dual-Polarized Antenna Array With High Port Isolation Through TM03/04 Modes Cancellation

Abstract

A new dual-polarized microstrip patch antenna array (MPAA) with high port isolation through TM03/04 modes cancellation is designed and reported in this letter. By introducing branches etched with slots between the units, the resonant frequency and impedance of TM03 mode are adjusted to be consistent with that of TM04 mode. First, TM03/04 modes cancellation decoupling scheme is applied to a two-element MPAA. And then, the proposed decoupling method is expanded to the compact decoupled dual-polarized four-element MPAA through multi-layer distribution. The co-linear port coupling is below -27 dB within the impedance matching bandwidth (S11 < -10 dB from 3.35 to 3.53 GHz), which is reduced by 20 dB from the original coupling. The maximum gain of 6.4 dBi is achieved, and the radiation efficiency is above 80%. Through miniaturized design, the proposed decoupling scheme achieves high port isolation and a stable radiation pattern. The proposed method may be expanded and greatly improve the performance in future decisions.