Compact UWB MIMO antenna with asymmetric coplanar strip feeding configuration

A compact UWB MIMO antenna composed of two elements is presented in this paper. The two antenna elements are fed by asymmetric coplanar strip (ACS). The radiator of the single antenna consists of half elliptical shape radiator. The two antenna elements are located side by side on FR4 substrate with size equal to 48 × 28 mm2. The edge to edge distance between the antenna elements is 0.23 λο at3 GHz. The two antenna elements are designed to operate in the UWB frequency band from 3 GHz to 11.5 GHz with return loss lower than -10 dB and isolation lower than -15 dB without using decoupling structures between the elements. The envelope correlation coefficient, diversity gain, and capacity loss which define the performance of MIMO antenna are within the required limits. The proposed antennas has been fabricated and measured. Experimental measurements were obtained and are in good agreement with simulation results, which verify that the proposed antenna is a good candidate for UWB MIMO applications. Moreover, the performance of the MIMO antenna is verified by computing the envelope correlation coefficient (ECC), diversity gain (DG), and channel capacity loss (CCL).