Compact High Isolation CPW Fed 4-Element UWB-MIMO Antenna with Special Isolation Structure

Abstract

This paper proposes a four-element ultra-wideband MIMO antenna. The antenna is composed of four half-cut monopole sub-elements, which are placed perpendicular to each other, adopting an improved CPW feeding method, and adding a special isolation structure to achieve high isolation. Combined with the new structure of the semi-circumferential ground, the impedance matching in the ultra-wideband range is realized. With many improvements and optimizations, excellent antenna performance has been achieved. Both simulation and test results show that the designed antenna working bandwidth can cover the 2.71-19.70GHz frequency band, the isolation within the entire bandwidth is greater than 18dB, the antenna’s radiation omnidirectionality is good, the radiation efficiency reaches more than 73%, and it has good gain characteristics, Envelope Correlation Coefficient (ECC) shows that the antenna can well meet the polarization diversity characteristics, the antenna has a compact overall size of only 38*38*1.6mm3. The antenna we designed can be used for portable wireless ultra-wideband applications.