Robust Wireless Power Receiver for Multi-Tone Waveforms

This paper presents a multi-tone wireless power receiver (WPRx) that can operate efficiently across various waveforms with a different number of tones. Conventional wireless power receivers have a significant efficiency dependence on the power levels and loading conditions. In this work, the conventional WPRx is also verified experimentally to be highly dependent on the input waveforms and their number of tones. Thus, a multi-tone WPRx is proposed using a configurable dc-to-dc voltage boost converter to track the optimal efficiency using external reference voltage. The proposed multi-tone WPRx is prototyped and characterized across different waveforms within a 10-MHz bandwidth at 2.4-GHz with a wide range of input power levels. The measured results show a significant suppression (of four times) in the efficiency variations across the different number of tones relative to conventional WPRx. For instance, at -10-dBm input power level, the standard deviation in the efficiency of the proposed WPRx, across different waveforms, is less than 1/4 that of the conventional WPRx while maintaining a very close average efficiency across these waveforms. While the conventional WPRx can be optimized only for a single type of waveforms, the proposed multi-tone WPRx can maintain a stable efficiency across different waveforms with minimum variations.