Optimization of the Power Transfer Through Human Body With an Auto-Tuning System Using a Synchronous Switched Capacitor

This brief presents an auto-tuning system for a wireless power transmitter that uses a variable synchronous switched capacitor for controlling the resonant frequency of the tank circuit of a half-bridge voltage-mode resonant converter. This original tuning topology does not need the addition of any bulky magnetic components and, consequently, naturally complies with the magnetic resonance imaging (MRI) compatibility regulations imposed to electromedical units used in the vicinity of MRI equipment.