Abstract
This paper reports a miniature low-profile denim textile 2-port MIMO (multiple-input-multiple-output) antenna for dual-bands: 5G sub-6 3.5 GHz and Wi-Fi 5.2 GHz wearable applications. This MIMO antenna has impedance bandwidths and peak gain of 310 MHz and 8.3 dBi and 950 MHz 13.0 dBi at 3.5 and 5.2 GHz, respectively. This MIMO antenna has a compact area of 0.078 λ(0)(2), with both antenna elements of the MIMO being a modified elliptical patch, L-shaped stubs for impedance matching, and a circular decoupling ring to achieve > 25 dB port isolation. The designed antenna is very tiny and integrated into the shirt's pocket. It is tested in two positions, i.e., hidden (integrated inside the pocket, for example, military applications) and visible (when integrated on the pocket surface for conventional communication). Moreover, the antenna's working is analyzed in these positions (hidden and visible), and it was found that it functions well in both 5G sub-6 GHz and Wi-Fi frequency bands with nearly close gain values and communication range. This MIMO antenna has a very small ECC (envelope correlation coefficient) of 0.006/0.002 in both frequency bands, which shows high channel isolation. The 1 gm/10 gm SAR (specific absorption rate) values at 3.5 and 5.2 GHz are 0.034/0.057 and 0.026/0.0132 W/Kg, respectively, substantially lesser than the recommended values of FCC/ICNIRP.