Design of a compact quad-radiating element MIMO antenna for LTE/Wi-Fi application

In this paper, a compact quad-element multiple-input-multiple-output (MIMO) antenna for LTE/Wi-Fi application is proposed. The four dual-elliptically tapered antenna elements are an orthogonal orientation to one another. The MIMO antenna comprises a cross-shaped stub between the quad-radiating elements and ring-shaped stripes between the partially ground planes that act as a decoupling element to suppress mutual coupling. The dimension of the designed MIMO antenna is (66×66×1.6)mm³. A prototype MIMO antenna was fabricated and S-parameters were measured in order to characterize the performance parameters of the MIMO antenna. The designed MIMO antenna operates at 2.3 to 2.7 GHz frequency band with high isolation exceeding 17 dB. Thus, the measured results give an envelope correlation coefficient below 0.04 and a channel capacity loss is lower than 0.6 b/s/Hz, which reasonably agrees with the simulated results.