Mutual Coupling Reduction for Dual-Band MIMO Antenna with Simple Structure

In this paper, a novel dual-band MIMO (multi¬ple input, multiple output) antenna for WLAN (wireless local area network) applications is presented. The MIMO antenna contains two dual-band antenna elements, each of which comprises a T-shaped monopole and a special ├-shaped stub resonator. Two operating bands with center frequencies of 5.5 GHz and 2.5 GHz are crested by the monopole of T shape and the stub resonator of ├ shape, accordingly. The ├-shaped stub also works as an isolation structure at the higher band, which can simplify the dual-band isolation design into a single-band problem. Moreo¬ver, the isolation is enhanced at the lower band by insert¬ing a metal strip which can cancel out original coupling. The inserted metal strip is the only additional decoupling structure in this design and has a simple texture with a compact size. The measured and simulated results reveal that the designed MIMO antenna can cover all the 2.4/5.2/5.8 GHz WLAN operating bands and within the recommended bands the isolations exceed by 20 dB