Power Receiving Circuit Design of Single-Ended Biological Capacitive WPT for Artificial Retina System

This paper proposes a power receiving circuit design for biological capacitive wireless power transfer (C-WPT) in an artificial retina system. To simplify the system design, we propose a single-ended C-WPT, using which the system can be designed based on the GND of the RF source. Thereby, the RF source and rectifier circuit can be designed as single-ended. First, we clarify the principle of the single-ended capacitive coupler and describe its design method. The proposed C-WPT does not require a balun. Thus, the coupler can be connected to a single-ended rectifier circuit. The element values required for the rectifier circuit connected by an equivalent circuit were calculated and the rectifier circuit was designed. Finally, the coupler and rectifier circuit were fabricated, and experimental measurements using porcine skin with a thickness of approximately 5 mm showed that the power received was 75.3 mW at 434 MHz.