Patent ID: 8487478

Claim:
An apparatus for wirelessly transferring power to a receive antenna of a receiver device, comprising: a transmit antenna configured to generate an electromagnetic field to wirelessly transfer the power to the receive antenna at a resonant frequency within a coverage area of the transmit antenna; an amplifier configured to output electric power to the transmit antenna for generating the electromagnetic field; a presence detector configured to detect a presence of the receiver device within the coverage area in the absence of physical contact with the receiver device, of using the electromagnetic field, and of receiving data communication from the receiver device, and configured to generate a presence signal in response to the detection of the presence of the receiver device; and a controller operably coupled to the presence detector and the amplifier and configured to adjust the output of the amplifier in response to the presence signal, the controller being further configured to cause power to be simultaneously transmitted to two or more receiver devices within the coverage area and to subsequently register each of the two or more receiver devices.