Isolation Enhancement of Metamaterial-Inspired Two-Port MIMO Antenna Using Hybrid Techniques

This brief utilizes hybrid isolation enhancement techniques to design a highly isolated two-port multiple-input-multiple-output (MIMO) antenna. Initially, an epsilon-negative transmission line-inspired antenna with circular polarization (CP) radiation is designed. Further, the same antenna is converted into a two-element MIMO configuration. Higher antenna isolation is obtained mainly due to two factors. Initially, multiple defected ground structure-based slots are inserted in the antenna ground plane to improve the antenna isolation by 23.5 dB. Secondly, placing an epsilon-and-mu-near-zero-based metasurface superstrate above the two-port MIMO configuration results in bandwidth ranges from 4.768-4.92 GHz and higher isolation of 51 dB. Finally, for analyzing the antenna performance in an actual environmental condition, the multilayer MIMO antenna is covered with a Teflon cavity and analyzed. Furthermore, the antenna port-1 provides right-handed CP radiation, while port-2 provides left-handed CP radiation, confirming the polarization diversity performance.

Automated summary

This paper designs a highly isolated two-port MIMO antenna using hybrid isolation enhancement techniques. First, an epsilon-negative transmission line-inspired antenna with circular polarization (CP) radiation is developed. Then, the same antenna is converted into a two-element MIMO configuration. By inserting multiple defected ground structure-based slots in the antenna ground plane and placing an epsilon-and-mu-near-zero-based metasurface superstrate above the two-port MIMO configuration, higher antenna isolation of 51 dB is achieved. The antenna's performance is analyzed in an actual environmental condition by covering it with a Teflon cavity, and the polarization diversity performance is confirmed.