Compact Four-Element MIMO Antenna Using DGS for WLAN Applications

A compact four-element multiple-input multipleoutput (MIMO) antenna is proposed for WLAN applications operating at 5.75 GHz frequency band. The overall volume of the antenna is 26 mm × 26 mm × 8 mm. Isolation between the antenna elements is improved by using defected ground structure (DGS). Operating frequency band of the MIMO antenna is 5.61-5.9 GHz, where isolation greater than 18.2 dB and envelope correlation coefficient (ECC) less than 0.02, and average channel capacity loss (CCL) less than 0.45 bits/s/Hz are obtained. The average peak realized gain of the four-element MIMO antenna is 1.61 dBi at 5.75 GHz with more than 76 % radiation efficiency in the entire operating frequency band.