MIMO Textile Antenna for 5.2 GHz Medical Wearable Monitoring Systems

Nowadays information monitoring system for continuous monitoring of patients is of great use in hospitals. However, there are not only a lot of limitations in the patient's movement and provision but also by transceiver devices and cables. Overcrowding on 2.4 GHz band has upraised problems in handling the number of devices through wireless LAN at a time in hospitals. It is well known that the 5 GHz band transmits and receives data at a larger speed in comparison with 2.4 GHz. In this paper, a simple technique with improved isolation Multiple Input and Multiple Output (MIMO) wearable antenna is investigated at 5.2 GHz frequency for the biological monitoring system. Flexible conductive cloth named MKKTN-360 is used as a patch with FELT as better insulation is combined into it. The compact MIMO antenna has design characteristics of $\vert \mathrm{S}11\vert \leqslant -10\ \text{dB}$ and $\vert \mathrm{S}12\vert \leqslant -48\ \text{dB}$ in whole 5.12-5.33 GHz band, whereas the dimension is only $100 \times 36$ mm2. The slotted ground structure makes the antenna radiation efficient (a measured gain realized 5.51 dBi at 5.2 GHz) in +Z direction away from the human body. The Specific Absorption Rate (SAR) is in a specified limit set by the Federal Communication Commission (FCC).