Study on wireless power and information synchronous transfer based on dual resonant coupling circuits

Wireless power transfer (WPT) technology realizes contactless power supply to equipments, e. g. mobile devices and rotating machinery, and avoids problems caused by power supply wires. However, in practical applications, such as medical electronic capsule and information feedback in WPT, the synchronous transfer of information is required. For such applications, a new dual resonant circuit is proposed in this paper, which is able to realize the synchronous transmission of power and information. Based on the analysis of the dual resonant circuit, the concept of the transfer factor is proposed to analyze the channel bandwidth and response time. The relationship between the transfer factor and the energy/information transfer performance is also studied. Experiments show that the energy transfer efficiency is above 70% when load is less than 10 Ω and the distance is less than 120 mm. By using the on-off-keying modulation mode, 50 kHz signal can be effectively transferred at 122 mm air gap with 1.31 Ω load.