A Low Mutual Coupling MIMO Antenna Using Periodic Multi-Layered Electromagnetic Band Gap Structures

A multi-layered electromagnetic band gap (EBG) structure is proposed and incorporated into a MIMO antenna to reduce unexpected mutual coupling between antenna elements. The proposed multi-layered EBG (ML-EBG) structure is comprised of an improved EBG and three loading patches with a same distance. The proposed ML-EBG structure is designed at 2.55 GHz and it is utilized in a MIMO antenna array with an edge-to-edge distance of 0.13 lambda to reduce the mutual couplings. The simulated and measured results have been put forward to prove that the mutual coupling has been reduced by 30 dB between the antenna elements compared to the MIMO antenna without the ML-EBG structure.