A Low-Profile Flexible UWB Wearable Antenna Loaded with Patch Slots and Defected Ground Structure for Wireless Body Area Networks
Md. Ariful Islam,
Md. Masud Rana,
Amrito Paul,
Abdul Kayum Muhammad Zakir Hossain and
Noor Badariah Asan
This study introduces a compact, low-profile ultra-wideband (UWB) wearable antenna designed for wireless body area network (WBAN) applications. The antenna incorporates a rectangular patch on a flexible jeans substrate, incorporating one patch slot, four identical edge slots, and a defected ground structure (DGS) with a compact dimensions of 23 mm × 30 mm × 1.5 mm. These slots and DGS enable the UWB operation with an excellent bandwidth while maintaining a good balance among the key performance parameters such as efficiency, gain, and SAR, which is the main contribution of this study. The antenna performance was analyzed using a four-layer human body phantom model that includes skin, fat, muscle, and bone layers. It operates across the frequency range of 2.82-11.25 GHz, covering the UWB range for wearable devices, and achieves a peak gain of 3.79 dBi, an average gain of 2.36 dBi, a peak efficiency of 63.36%, and an average efficiency of 52.88%. In addition, the obtained SAR values are 0.549 W/kg and 0.391 W/kg at 5 GHz, and 0.0727 W/kg and 1.97 W/kg at 9 GHz for 1 g and 10 g tissue standards, respectively, complying with SAR regulatory standards. Moreover, bending analysis validated its stable performance under various angles and deformation conditions. The fabrication and on-body testing of the proposed antenna exhibited a bandwidth of 1.38-12 GHz, demonstrating compliance with simulations. Finally, a human body temperature monitoring prototype was developed, which validates its suitability for wearable WBAN applications.
