Wearable Magnetoinductive Waveguide for Low-Loss Wireless Body Area Networks

Abstract

A novel approach of wearable magnetoinductive waveguide (MIW) is introduced for wireless body area network (WBAN) communications that brings forward significant advances over state-of-the-art. The MIW consists of series of electrically small resonant loops worn upon the human body to support magnetoinductive waves (MI waves) for low-loss/low-power WBANs. Compared to previous approaches, the proposed MIW exhibits 63 dB lower loss, translating conventional power levels of mW down to μW or nW. In this work, we introduce the operating principle of MIW WBAN through underlying theory and dispersion diagrams. The proof-of-concept numerical and experimental results are reported for frequency bands centered around 40.4 and 80.7 MHz for a cylindrical human limb and are found to be in excellent agreement. Design guidelines are extensively discussed to accommodate several possible scenarios (frequency selection, gap between the loops, number of loops, and loop radius) along with practical considerations including loop tilts, anatomical limbs, limb movements, unequal loop gaps, and loop failure. Specific absorption rate (SAR) calculations confirm that this technology is highly safe for human use. A bit error rate (BER) analysis further demonstrates that the MIW can form a high-quality communication channel for WBAN. Overall, the reported approach unveils a new possibility of low-loss and seamless WBANs.