Wearable Planar Magnetoinductive Waveguide: A Low-Loss Approach to WBANs

We introduce an alternative approach for wireless body area networks (WBANs) that rely on wearable planar magnetoinductive waveguides (MIWs) placed upon the body to reduce loss by 50–60 dB versus the conventional state of the art. Compared to our recently reported MIW WBANs that rely on axial rather than planar electrically small resonant loops, this approach: 1) overcomes the inherent constraints of anatomical geometry; 2) provides uniform WBAN implementations across the entire human body or different human bodies; 3) allows for frequency scalability over a wide frequency range; 4) exhibits more degrees of freedom for design optimization; and 5) provides significantly better performance (28.92 dB loss improvement for an example 5-loop design). In this work, we discuss the operating principle and validate the idea via a theoretical dispersion model. Numerical full-wave simulations are then presented and further validated via
in vitro
experimental results on a canonical torso model. Design optimization is subsequently performed for performance (loss and bandwidth), accompanied by a reasoning analysis based on the theoretical dispersion model. Specific absorption rate (SAR) studies confirm electromagnetic safety, while frequency scalability and tolerance to anatomical curvature further highlight its potential. Overall, the reported approach significantly advances the state of the art and shows promise for low-loss WBANs of the future.