Design of High-isolation Band-notched Via-fed UWB MIMO Antennas with Multi-Objective Optimization

High isolation band-notched via-fed MIMO antennas are proposed for UWB systems. The MIMO antennas consist of two via-fed monopole UWB antennas which share a common area connecting to the radiators. Four symmetrical fish-bone shaped slits are etched on the common area and optimized by MOEA/D-DE to achieve isolation of 22dB. Moreover, three resonators optimized by MOEA/D-DE are added to achieve sharp roll-off notched band or three notched bands. For demonstration, the first design is band-notched UWB MIMO antennas with sharp selectivity. Both simulation and measurement show that isolation higher than 22dB and a second-order notched band of 5.15-5.85GHz are achieved in the UWB band. With the proposed antenna and design technique, the second design achieves high isolation and three notched bands (3.3-3.6GHz, 5.15-5.85GHz, 7.25-8.4GHz) for UWB MIMO antennas.