Meander-line electromagnetic bandgap structure for UWB MIMO antenna mutual coupling reduction in E-plane

This paper presents an ultrawideband (UWB) meander-line electromagnetic band gap structure for mutual coupling reduction in E-plane of MIMO antennas operating in the frequency range 3.1–10.6 GHz. Planar UWB MIMO antenna with edge to edge gap of 8 mm has been designed and fabricated on FR4 substrate with dielectric constant 4.4 and height 1.6 mm. An array of four unit cells of electromagnetic bandgap structures arranged in top and bottom layers of the substrate connected through vias has been placed in between antennas to achieve the reduced mutual coupling in the ultrawideband range. Minimum 1 dB and maximum 14 dB reduction in mutual coupling is achieved for 3.4–8 GHz frequency range. Minimum 8 dB and maximum 24 dB mutual coupling reduction is achieved for range of 8–10.6 GHz. Measured results and surface current of MIMO antennas also validate the mutual coupling reduction. Envelope correlation coefficient (ECC) less than 0.02 and channel capacity loss (CCL) less than 0.5 bps/Hz are achieved.