Frequency Selection for High Efficiency Wireless Power Transfer

The analysis of wireless power transfer efficiency is currently limited to a priori choice of spot frequencies. This paper presents a wireless power transfer system for applications in displays which examine transfer efficiency for a broad range of resonant frequencies. The system provides a dc voltage output, achieved using self-oscillation in coupled inductor-capacitor resonator pair. Measurement results corroborate well with simulations, enabling optimization of transfer efficiency with respect to different system parameters including resonant frequency. It turns out that the system efficiency is maximized for a resonant frequency in the range of 0.2 to 10 MHz.