Design Wideband MIMO Antenna for UWB Applications

The main challenges of designing an antenna for modern wireless communication represented size reduction and mutual coupling. In this paper, a four-element multiple-input multiple-output (MIMO) ultra-wideband (UWB) antenna is proposed. Each element has two ports with dual-polarized patches to reduce the result of reciprocal coupling, increase the capacity, and keeps a proper size. Quasi-circular geometric shape containing slots has been placed in front of the patch of the proposed antenna to reduce the impact of mutual coupling. The four elements have been integrated with integrate eight ports with an area of 60.59×60.59 mm2 with a rogers insulation layer where the single antenna element and MIMO antenna are simulated by the CST STUDIO 2019 program. The resulting operating frequency of the MIMO antenna is 6.18 GHz with a bandwidth of 4.79 GHz (4.93-9.72) GHz at -10 and a return loss of -45 dB at resonance while the operating frequency for the single antenna element is 6.37 GHz with a band of 4.72 GHz (4.93-9.65) GHz at -10 dB and return loss of -50 dB at resonance. The MIMO antennas achieved an envelope correlation coefficient (ECC) less than 0.0005 and an acceptable gain (around 9 dB) while diversity gain (DG) was equal to approx 10.