Wearable antenna supporting dual physical layers for IEEE 802.15.6 WBAN

Abstract Integrated wearable healthcare systems enable the continuous monitoring and collection of physiological data. In these systems, wearable devices and sensors are interconnected through on-body communication, with some devices used for off-body communication. The antennas employed for such devices must be small without compromising the resulting performance. In this study, we propose a dual-mode antenna that supports two physical layers: human body communication (HBC, 21 MHz band) and narrowband wireless communication (NBWC, 2.4 GHz band). To reduce the size of the developed antenna, the HBC electrodes are integrated into the ground plane of a conventional patch antenna, and a single feed point is shared. We evaluate the antenna through numerical electromagnetic field simulations conducted using a multilayer arm phantom. The results show that the antenna maintains a reflection coefficient below − 10 dB across the NBWC band, ensuring reliable off-body links, and yields a simulated reflection coefficient of − 4 dB in the HBC band. A radiation pattern analysis performed at 2.4 GHz reveals a nearly omnidirectional profile in free space and an efficiency level within the acceptable 20–40% range when the system is worn. In the HBC mode, the arm phantom increases the coupling effect by more than 50 dB. The specific absorption rate values remain below international safety limits, confirming the biocompatibility of the antenna.