Mutual Coupling Reduction in UWB-MIMO Antenna Using Circular Slot EBG Structures

In this paper, a compact Ultra Wide Band (UWB) Multiple Input Multiple Output (MIMO) antenna using circular slots Electromagnetic Band Gap (EBG) structures operating in frequency band from 3.1 GHz to 10.6 GHz is presented. The size of this compact antenna is 26 x 33mm(2). In wireless communications, such as WLAN, 4G, and 5G, MIMO has become an essential element. However, the major limiting factor of MIMO systems is mutual coupling due to the smaller spacing between multiple antennas, which reduces spatial diversity, antenna gain and can also result in unwanted interference and cross-talk between antenna elements. To enhance antenna performance and reduce the mutual coupling, EBG structures are used. Incorporation of EBG structures in MIMO antenna eliminates surface wave propagation, which reduces the mutual coupling. In this work, the design of a dot notch shaped UWB-MIMO antenna with a circular slot EBG structure is proposed. Results presented here are simulated by using CST microwave software studio. From the results it can be observed that the proposed antenna has bandwidth of 3.1 GHz-10.6 GHz. It exhibits 6.72 dB peak gain and reduces the mutual coupling considerably, i.e., more than -28dB.