Study on Dual-Band Four-Port MIMO Antenna with High Isolation

A dual-band four-port MIMO antenna with high isolation is proposed in this paper. The two operating bands of the MIMO antenna were located at 3.5-GHz and 4.9-GHz. The antenna was composed of four ring monopole elements with microstrip-fed, which were symmetrical placed on the substrate of the antenna. Meanwhile, the rectangle slot, the protuberance, and the modified serpentine structure were introduced into the antenna to enhance the isolation between each monopole element. This letter reports the processes of the design and the experimental test for this MIMO antenna. From the experimental results, less than -15dB isolation were obtained within the operation bandwidth, which is in accordance with the simulation results.