A Wireless Power and Information Simultaneous Transfer Technology Based on 2FSK Modulation Using the Dual Bands of Series–Parallel Combined Resonant Circuit

In this paper, a new wireless power and information simultaneous transfer (WPIT) technology based on binary frequency shift keying (2FSK) modulation using the dual bands of a series-parallel combined resonant circuit (SPRC), SPRC-2FSK-WPIT technology, is proposed. Conventional 2FSK-WPIT technologies commonly employ single resonant band, and due to the insufficient utilization of system resonance, they have inherent disadvantages, such as low efficiency and low system quality factor. In the proposed technology, the system employs dual resonant bands of the SPRC and both of the system carriers use the resonant frequencies, and so the disadvantages of the conventional 2FSK-WPIT technology are eliminated. Optimal design of the SPRC-2FSK-WPIT system is conducted. In the optimized system, the two carriers have similar power and information transfer characteristics, and so a high WPIT performance, including stable power transmission, is guaranteed. The proposed technology is validated by experimental results. The experimental prototype shows up to 20 kb/s of communication rate with maintaining the power transfer efficiency over 85% at the distance of 50 mm.