CPW-Fed Slot Antenna for Medical Wearable Applications

In this paper, a flexible antenna with a simple structure, small size (<inline-formula> <tex-math notation="LaTeX">$15mm\times 17mm\times 1mm$ </tex-math></inline-formula>), and light weight for medical wearable applications is proposed. The antenna consists of slot radiation elements fed by a coplanar waveguide structure and a floating ground. Flexible conductive cloth MKKTN260 is used to fabricate the antenna, while felt with good insulation is used as the substrate. The measured impedance matching bandwidth (<inline-formula> <tex-math notation="LaTeX">$\left |{ {S_{11} } }\right |$ </tex-math></inline-formula>less than −10dB) of the antenna is from 5.578 to 5.898GHz, which can cover the whole ISM 5.8GHz band (5.725–5.825GHz) and perform good wearable radiation characteristics. The floating ground structure and the interaction between slots make the antenna radiated efficiently (the measured peak realized gain is 4.85dBi at 5.8GHz) to the +Z direction, which is away from the human body. Meanwhile, without any specially designed reflecting structures, the specific absorption rate value is below the criterion set by the FCC and ICNIPR. The bending configurations are also studied for this antenna.