Extended coupling-range wireless power transfer using 0× / 4× resonant regulating rectifier

Coupling coefficient variation due to the lateral or angular misalignment and axial distance variations changes the DC voltage and power delivered to the load. In this paper, a resonant regulating rectifier (R
³
) topology is proposed based on a switchable quadrupler in order to regulate the output voltage in a wide coupling-range without making use of DC-DC converters or linear regulators. The load voltage is compared with a reference voltage to determine the mode of operation of the quadrupler: ON (4×) or OFF (0×). The pulse width of the comparator output and the duration of ON/OFF mode is determined in a loop so that the average of the load voltage stands at 20 V. The system is implemented on the printed circuit boards (PCBs) for transferring power at 125 kHz. The measurements show that the proposed R
³
supplies a 200 Ohm load with constant 1.88 W of power over 4 to 22 mm axial distance and up to 15 mm lateral misalignment. The results indicate that this system is able to provide a regulated voltage wirelessly with less regulation error and more extended power transfer range comparing with similar studies.