Decoupling of 2 × 2 MIMO Antenna by Using Mixed Radiation Modes and Novel Patch Element Design

This article presents a novel and simple method for the decoupling of a 2\times 2 MIMO antenna array. Two distinct radiation modes, with different patterns and polarizations, are created by a novel patch element design. This new configuration enables the excitation of additional coupling paths between antennas, and ultimately the neutralization of mutual coupling. Since the two radiating modes are generated by the same patch element, the proposed MIMO antenna also features simple structure and compact size. For verification, a 2\times 2 MIMO antenna with center-to-center spacing of 0.475\lambda _{0} is prototyped and characterized. Simulation and experimental results reveal that the proposed design can offer enhanced port isolation, antenna efficiency, and pattern diversity.