Dual-band MIMO antenna using double-T structure for WLAN applications

A dual-band multiple-input-multiple-output (MIMO) antenna is proposed for the wireless-local-area-network (WLAN) applications in the 2.4-GHz and 5.2-GHz bands. The antenna consists of two double-T monopole elements with microstrip-fed and symmetrically placed on a substrate. To enhance isolation between the two monopole elements, three slots are cut on the ground plane on the other side of the substrate. The longer slot is used for better isolation in the 2.4-GHz band, while the two shorter slots are used for the 5.2-GHz band. Simulation and measurement are used to study the antenna performance in terms of S parameters, radiation patterns, realized gain, efficiency, and envelope correlation coefficient. Results show that the MIMO antenna has the two operation bands (2.20-2.75 GHz and 5.09-5.50 GHz) with mutual coupling of less than -15 dB and envelope correlation coefficient of less than 0.1, making it a good candidate for WLAN applications.