High isolation dual-port MIMO antenna

A compact dual-port multiple-input multiple-output (MIMO) antenna is proposed for 2.4 GHz wireless local area network systems. The radiation element consists of a monopole and a patch ring with two cuts, through which a coplanar waveguide port and a slotline port are constructed. The current distributions of the proposed antenna for both ports excited are simulated and analysed, respectively. According to the measurement results of the manufactured antenna prototype, the isolation between these two ports over the operating frequencies is better than -35 dB and the cross-polarisation radiation levels are less than -45 dB at the main direction. Finally, the proposed antenna has excellent isolation not only at the feed ports, but also in the radiation patterns.