Wideband Dual-Polarized Magnetically Coupled Patch Antenna Array With High Port Isolation

Abstract

A dual-polarized magnetically coupled patch antenna array with high isolation is presented in this paper. The proposed ${{1}} \times {{2}}$ antenna array is composed of two square patches printed on the horizontal substrate, two pairs of feeding structures printed on the two vertical substrates, a pair of metal cavities and a novel artificial periodic structures (APS) composed of metal strips etched vertically on the ground plane. Each feeding structure is orthogonally mounted and excites the square patch magnetically. The feeding structure comprises a metal loop or quasi-loop printed on one side of the vertical substrate and an open-ended transmission line printed on the other side. The metal cavities and APS can further improve the port isolation between array elements. The simulation and measurement results of single antenna element demonstrate its extremely high port isolation (better than 45 dB over 20% impendence bandwidth for ${\text{VSWR}} 1.5). For the array, numerical and experimental results show that the port isolation with same polarization can be improved to over 45 dB across the frequency band of 2.5–2.7 GHz. The proposed antenna array achieves wide bandwidth with very high isolation, high gain, and high radiation efficiency.