A compact planar UWB MIMO antenna using modified ground stub structure

Abstract

A novel UWB-MIMO antenna with high isolation is presented. The proposed antenna consists of two identical UWB elements. Each antenna element is evolved from the off-center-fed patch antenna and its operating frequency band covers the ultra-wideband. The modified ground, as part of the antenna radiator, can improve isolation by propagating through the restraining surface. In addition, the ground stub between the two elements, changes the surface current distribution, makes the surface current truncated and drawn, and obviously reduces the coupling between the ports, so that the antenna always has good isolation in the UWB. The miniaturized MIMO antenna with a size of only 30 × 40 mm² and measured mutual coupling lower than −18 dB, covers the 3.1–10.6 GHz UWB band, suitable for UWB wireless communication system.