Load-Independent Push–Pull Class E$ ^2$ Topology With Coupled Inductors for MHz-WPT Applications

This article investigates the modeling and implementation of load-independent operation for push–pull Class E topology with coupled inductors. The analytical is first presented provides a new design methodology, which distantly improves soft-switching performance, load regulation, efficiency compared conventional inductor-coupled topology. An LCC-S resonant $ ^2$ converter, combines inverter active rectifier, proposed MHz-wireless power transfer (MHz-WPT) applications. rectifier maintains soft switching, constant voltage gain, zero-phase-angle input at various loads. A three-winding magnetic structure also to improve inductors by enhanced self-inductance, features more effective harmonic suppression lower losses volumes. By methodology improved structure, converter negligible contents switching conversion ratio over entire range. 6.78-MHz WPT prototype was built verify detailed parameter hardware implementation. realizes zero-voltage an approximately gain +5/ notation="LaTeX">$-$ 4% variance from no-load 320-W output power. measured dc–dc reaches 89.3% 210 W.