Misalignment analysis of resonance-based wireless power transfer to biomedical implants

Abstract

We present a power transfer sensitivity analysis of a four-coil resonance-based wireless power delivery system that is used to provide energy to a small-size biotelemetry system implanted into non-human freely moving subjects. Both axial and angular misalignments have been evaluated, with calculations for the worst-case misalignment of 15mm axial distance and 50° angular separation for a minimum constant power supply of 0.5mW in the load resistor. Analytical results have been validated with electromagnetic field simulations. Discrete level design of a wirelessly powered implant incorporating this analysis is also presented.