A Novel Parasitic EBG Structure to Enhance Mutual Coupling for 2.45 GHz MIMO Antenna

In the 5.0 industrial era, antenna technology has been evolving very rapidly. Multiple Input Multiple Output (MIMO) is expected as a method to increase channel capacity and reliability. The structure of the MIMO antenna should be observed to avoid the mutual coupling between elements. A novel circular square parasitic electromagnetic band gap (EBG) structure is evaluated for MIMO in 2.45 GHz frequency to improve the mutual coupling effect. A simple two identical circular patches design with the multiple parasitic EBG structure is optimized using HFSS. The overall dimensions of the microstrip antenna because of the design optimization are 50.3 mm x 115.7 mm. The results demonstrate that the antenna has slightly -16 dB of S11 by simulation and measurement, whereas the mutual coupling effect was decreased at slightly -23.5 dB and -25.08 dB, respectively.