Ultrawideband MIMO/diversity antenna using CSRR structure for isolation enhancement

A novel compact ultra-wideband multiple-input-multiple-output (MIMO) antenna (of two elements) is proposed. Two circular radiating elements are arrange perpendicularly to reduce mutual coupling. By inserting a complementary split ring resonator (CSRR) in the ground plane, high isolation between two ports is further enhanced. Measured results show the proposed antenna has a wide impedance bandwidth from 3.1 to 10.6 GHz and good isolation (better than -20 dB at most of the band). Due to these highly desirable characteristics, the MIMO antenna is expected to be a good candidate for UWB application.