A Patch MIMO Antenna With High Isolation Using Extended Fence Strip

A patch MIMO antenna with isolation ≥51 dB is proposed for the application of wireless communication systems, which is composed of two close-placed patch elements and one simple decoupling structure (extended fence strip, EFS). The EFS only consists of a metal strip and seven short pins; the parameter tuning and performance optimization are easy to be implemented. It can effectively suppress the near-field coupling and the surface wave coupling to produce two controllable transmission zeros within the operation band, but without effect on the impedance matching of the two patch elements. Therefore, a port-to-port isolation of 51dB is achieved by the two patch elements with an edge-to-edge distance of only 0.12λ₀. The decoupling mechanism of the EFS is revealed by investigating the H-field and the current distributions. With a profile of 0.08λ₀, the proposed patch MIMO antenna is implemented, and the results shows a -10dB bandwidth of 3.3-3.6 GHz (covering N78), an average in-band gain of 7.5 dBi, a high port-to-port isolation ≥51dB, and an envelope correlation coefficient (ECC) ≤0.002.