Simultaneous Wireless Power and Information Transmission Based on Harmonic Characteristic of Soft-Switching Inverter

The existing simultaneous wireless power and information transmission (SWPIT) technology used for wireless power transfer (WPT) systems is seriously plagued by the interference between the power and information transmission and the complex design of the information transmission and receiving circuits. To combat these problems, this article proposes a novel SWPIT method, which does not need additional information transmitting or receiving coils. The stroboscopic mapping model of the WPT system is established first, and the soft-switching points of the dc-ac inverter are derived and compared for better utilizing deviation frequency enlargement effect (DFEE) to transfer power and information simultaneously. Subsequently, the information detection circuit is designed based on DFEE. The impacts caused by the detection circuit on the power and information transmission are analyzed in detail. Then, the parameters of the detection circuit are optimized for minimizing the mutual interference between the power and information transmission. Finally, a 50 W experimental platform is established to verify the correctness and effectiveness of the proposed SWPIT strategy. The experimental results show that the information transmission rate can reach up to 16 kbps, the load voltage fluctuation can be controlled below 3%, and the efficiency of the whole system can be maintained at 90%.