A small footprint ultra-wideband multiple-input multiple-output antenna

A compact planar Ultra-wideband Multiple-input Multiple-output antenna with two identical monopoles is presented in this paper. These monopoles are kept very close to each other at a distance of 5.5mm. Wideband isolation is obtained over the complete spectrum with a novel decoupling structure attached to the ground plane composed of an inverted y-shaped stub and a combination of horizontal and vertical strips attached to each other. The analysis of the antenna performance with and without the decoupling structure is provided to demonstrate the effectiveness of the proposed decoupling structure. The proposed antenna measures only 43×28 mm² and it is suitable for small handheld devices and future technologies based on UWB-MIMO.