Wearable Dual-Band Dual-Polarization Button Antenna for WBAN Applications

This letter proposes a wearable dual-band dual-mode button antenna for wireless body-area network applications. It covers the 2.45 and 5.8 GHz Industrial, Scientific, and Medical bands. The two operating modes of the antenna are designed to share a common radiator with different functionalities for distinctive communication requirements. The antenna operates from 2.32 to 2.57 GHz as a top-loaded monopole antenna with linear polarization, which is applicable for on-body communications due to its omnidirectional radiation pattern. In contrast, it works as a crossed-dipole antenna in its higher operation band extending from 5.72 to 7.85 GHz, in which it exhibits broadside radiation with circular polarization suitable for off-body communications. The experimental characterization on the fabricated antenna prototype, both in free space and proximity to the human body, proves that the antenna operates as anticipated with dual-band and dual-polarization characteristics for wearable applications.