High-Isolation, Wideband Two-Element MIMO Antenna with Novel Decoupling Coupling Structure for Millimeter Wave 5G Wireless Applications

The article presents a compact, novel, inverted Pshaped antenna operating at Ka-band. The antenna is designed to resonate at frequency f
0
= 30 GHz. The single-element antenna is expanded to a two-element MIMO. Various antenna orientation arrangements are studied to comprehend the effect of mutual coupling. Out-of-these mirrored antenna elements facing outward have resulted in better isolation of 22.95 dB with a bandwidth of 27.30-34.83 GHz. However, a slight mismatch in reflection coefficients is observed due to minor surface wave coupling. Further, a novel decoupling structure with a combination of inverted H- and T-shaped is engraved in the ground plane to enhance the isolation and antenna performance. The overall MIMO antenna profile is 1.3λ
0
x 0.52λ
0
. It resulted in a maximum isolation of 35.17 dB with a bandwidth of 26.3633.64 GHz. The maximum achieved gain is 3.2 dB. The proposed antenna is validated with diversity performance and is suitable for 5G wireless applications.