Conformal ultra-compact narrowband 60.0 GHz four-port millimeter wave MIMO antenna for wearable short-range 5G application

This research reports a conformal ultra-compact millimeter-Wave microwave access narrowband four-port MIMO_60.0 GHz antenna designed for 60.0 GHz future high-speed wireless applications. The proposed 60.0 GHz MIMO_60.0 GHz antenna radiating electromagnetic energy occupies a minimal space of 16 × 16 mm² with a rectangular patch connected to defected microstrip structure on one-plane of RogersRTDuroid^TM5880 substrate with a thickness of 0.254 mm and complete-ground on the opposite plane. The proposed MIMO_60.0 GHz EM-wave antenna offers measured impedance bandwidth of 58.925 GHz–60.66 GHz with S₁₁ = −35.79 dB at 59.945 GHz. The proposed MIMO_60.0 GHz technology antenna offers a peak gain of 10.56dBi at 60.0 GHz. The thin substrate is characterized for conformal bending at 15^◦, 30^◦, and 45^◦ with no change in the center resonance frequency which is centered at 60.0 GHz. The MIMO_60.0 GHz antenna also offers good diversity performance including ECC_60.0 GHz \(\le 0.50\) $\le 0.50$ , DG_60.0 GHz \(\cong\) $\cong$ 10.0 dB, TARC_60.0 GHz \(\le 0.0\) $\le 0.0$  dB, CCL_60.0 GHz \(\le\) $\le$ 0.40 b/s/Hz and MEG_port1/MEG_port1 \(\cong\) $\cong$ 0.0 dB which values are under the standard-ideal values. The SAR values for single and four-port MIMO antenna corresponds to \(\le\) $\le$ 1.60 W/Kg and all the above features of the proposed MIMO_60.0 GHz antenna make it suitable for wearable (conformal) wireless applications and future mobile users.