Wireless charger system that has variable power / adaptive load modulation

Abstract

A wireless charging system that includes in-band communication includes: a source device, including: at least a transmitter coil for providing a wireless charging power which is modulated according to a reflected impedance of at least a target device; and at least the target device, oriented on and magnetically coupled to the source device, for receiving the charging power. The target device includes: a receiver coil, loosely coupled to the transmitter coil, for receiving the charging power; a variable resistor loading the receiver coil; and a power detection and modulation circuit, for determining a size of the charging power, and providing a modulation control signal to the variable resistor according to the size of the charging power, for varying the resistance of the variable resistor in order to control an impedance of the target device which will be reflected at the source device.

Dependencies are inferred from the claim text.