Compact 13.56 MHz Wireless Power Transfer Architecture Using Self-Resonant Coils with Inherent Source Power Limiting
Zixuan Yi,
Ziheng Li,
Xiaojun Tao and
Meiling Li
Megahertz wireless power transfer (MHz-WPT) enables compact resonant components; yet the matching, compensation, and filtering stages used in conventional systems can dominate loss and standby dissipation at MHz operation. To address this issue, this work proposes a compact 13.56 MHz WPT architecture in which impedance transformation is integrated into the resonant hardware. A self-resonant transmitting coil is co-designed with a Class-E power amplifier to shape the reflected load toward the optimum operating condition, thereby removing the external compensation network, the additional matching stage, and the lumped-element LC output filter. The analysis shows that, when the receiver is removed, the effective load becomes dominated by the transmitter resistance, inherently suppressing delivered power without sensing or closed-loop control. A prototype delivers 9 W over 30 mm with 81.5% end-to-end DC–DC efficiency, while under receiver absence, the DC input power decreases from 11 W to 1.15 W. These results demonstrate a simplified and robust MHz-WPT architecture with reduced component count and inherently low standby dissipation.
