Variable-Frequency Pulse Width Modulation Circuits for Resonant Wireless Power Transfer

In this paper, we develop a variable-frequency pulse width modulation (VFPWM) circuit for input control of 6.78-MHz resonant wireless power transfer (WPT) systems. The zero-voltage switching relies on the adjustments both duty cycle and frequency class-E amplifier used in WPT as transmission unit. High-frequency wave integrated circuits exist, but some have insufficiently high or unfavorable resolution tuning. novelty work is VFPWM design that put together. A voltage-controlled oscillator (VCO) radio capacitor-coupled difference amplifiers are to simultaneously perform tuning required applications. Different topologies compared analytically numerically. most favorable topology, enabling independent cycle, employed experiments. experimental results demonstrate validity novel VFPWM, which capable operating at has ratio adjustable from 20% 45% range applicable