Simultaneous wireless power and data transfer based on 4FSK modulation using the four splitting frequencies of series-parallel combined resonant circuit-based system

In this paper, a new simultaneous wireless power and data transfer method is proposed based on 4FSK modulation using the four splitting frequencies of series-parallel combined resonant circuit (SPRC) based WPT system. Features of SPRC-based WPT systems, including two resonance frequencies, circuit quality factors, system topologies, system quality factors and four splitting frequencies, are investigated. Based on that an optimum condition of the system to have similar quality factors at the four splitting frequencies is derived and a 4FSK modulation-based simultaneous wireless power and data transfer system is designed. An experimental prototype of the proposed system is constructed and the simultaneous transfer feasibility of power and data based on 4FSK modulation is validated. The prototype shows stable power transfer and up to 4kbps data rate in the distance of 20 cm, where the carrier frequency hops between four splitting frequencies spreaded in 40 to 62 kHz range.