A highly flexible and low-profile metasurface antenna for wearable WBAN systems

Recent years have witnessed the popularity of wearable devices. These devices use Wireless Body Area Networks (WBANs) for healthcare monitoring, personalized tracking, and various other applications. An important component of these devices is the wearable antenna that provides reliable and efficient wireless communication between body-worn sensors and external devices. This paper presents a novel metasurface-based wearable antenna for WBAN applications. By incorporating metasurfaces into the antenna design, achieving enhanced performance is possible. The design was tested using four flexible substrates: wool, paper, fleece, and felt. The paper substrate was chosen because of its superior performance. The dimensions of the antenna are 30 mm x 20 mm, and a 5 ×3 metasurface is used, whose unit cell comprises a square patch. Simulation and experimental results have been performed to measure the radiation pattern, return loss, and gain. A good corroboration is observed between the measured and simulated results. The antenna resonates at three frequencies and offers wide-band resonance characteristics when backed by the metasurface. The peak gain of the antenna without the metasurface was less than 4 dB, but when backed by the metasurface, the peak gain was enhanced to approximately 6 dB. Also, it has been observed that the designed antenna’s performance is not significantly affected by the radius of curvature, making it ideal for on-body measurements. This design can inspire further research on low-cost paper substrate-based antennas for WBAN applications.