Printed MIMO antenna system of four closely-spaced elements with large bandwidth and high isolation

A compact wideband printed MIMO antenna system (of four elements) with high isolation is presented. The proposed MIMO antenna system with an overall lateral size of only 0.43λ× 0.43λ can offer 22.8% bandwidth (1.63-2.05 GHz) and isolation of better than 24 dB. The measured gain is larger than 2.72 dBi over the whole band, and the calculated envelope correlation coefficient is better than 0.01. The radiation patterns and MIMO channel capacity are also measured.