Compact Dual Band-Notched UWB MIMO Antenna With High Isolation

A compact dual band-notched ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna with high isolation is designed on a FR4 substrate (27 x 30 x 0.8 mm(3)). To improve the input impedance matching and increase the isolation for the frequencies >= 4.0 GHz, the two antenna elements with compact size of 5.5 x 11 mm(2) are connected to the two protruded ground parts, respectively. A 1/3 lambda rectangular metal strip producing a 1.0 lambda loop path with the corresponding antenna element is used to obtain the notched frequency from 5.15 to 5.85 GHz. For the rejected band of 3.30-3.70 GHz, a 1/4 lambda open slot is etched into the radiator. Moreover, the two protruded ground parts are connected by a compact metal strip to reduce the mutual coupling for the band of 3.0-4.0 GHz. The simulated and measured results show a bandwidth with vertical bar S-11 vertical bar <= -10 dB, vertical bar S-21 vertical bar <= -20 dB and frequency ranged from 3.0 to 11.0 GHz excluding the two rejected bands, is achieved, and all the measured and calculated results show the proposed UWB MIMO antenna is a good candidate for UWB MIMO systems.