CRLH Unit Cell Loaded Triband Compact MIMO Antenna for WLAN/WiMAX Applications

A compact triple-band two-element multiple-input-multiple-output (MIMO) antenna is designed in this letter. The triple-band characteristic is achieved by loading a modified square-loop antenna with composite right/left-handed (CRLH) unit cell. Open-ended slot is etched from ground plane of the MIMO antenna to improve the isolation. The two-element antenna is well suited for WLAN/WiMAX applications as it covers 2.37-2.64, 3.39-3.58, and 4.86-6.98 GHz. Both envelope correlation coefficient and channel capacity loss are within their acceptable limits. Moreover, the antenna exhibits quasi-omnidirectional radiation pattern in xz -plane, which is useful for portable wireless communication devices.