Abstract: The present invention provides a modulation circuit and a method for modulating a wireless power transfer circuit. The modulation circuit has a switching circuit having a first state and a second state. The modulation circuit also has a modulation mode in which the first state defines a normal state and the second state defines an operative state. In the operative state, the modulation circuit modulates an electrical parameter of the wireless power transfer circuit in a modulation direction. The modulation circuit is configured to apply a trial modulation to the electrical parameter to determine whether the modulation direction is in a desired modulation direction. The modulation circuit is also configured to apply a modulation translation if the modulation direction is not in the desired modulation direction, with the modulation translation changing the modulation mode such that the modulation direction is in the desired modulation direction.

Abstract: Various circuit configurations and topologies are provided for single and multi-phase, single-level or multi-level, full and half-bridge rectifiers in which diodes are replaced by combinations of voltage-controlled self-driven active switches, current-controlled self-driven active switches and inductors in order to reduce the effects of conduction loss in the diodes.

Abstract: The present invention provides a universal demodulation circuit, a load modulation circuit and associated method, and an associated power transfer system, all suitable for use in wireless power transfer. A power receiver with signal strength detection is also provided. Modulation of the impedance of the demodulation circuit is determinable by detecting the amplitudes of a first and a second electrical parameter, thereby demodulating data communicated by modulation of the impedance of the demodulation circuit. The modulation circuit has a communication modulator to modulate the impedance of the modulation circuit, to a predetermined minimum modulation depth, thereby to communicate data.

Abstract: The present invention provides a universal demodulation circuit, a load modulation circuit and associated method, and an associated power transfer system, all suitable for use in wireless power transfer. A power receiver with signal strength detection is also provided. Modulation of the impedance of the demodulation circuit is determinable by detecting the amplitudes of a first and a second electrical parameter, thereby demodulating data communicated by modulation of the impedance of the demodulation circuit. The modulation circuit has a communication modulator to modulate the impedance of the modulation circuit, to a predetermined minimum modulation depth, thereby to communicate data.

Abstract: The present invention provides an AC-DC converter and AC-DC conversion method for converting an AC input provided by a power transfer winding. The AC-DC converter includes a rectifying means for rectifying the AC input into a rectified output, and a control means for controlling the rectifying means based on a comparison between a reference signal and a voltage feedback signal, the voltage feedback signal being based on the rectified output.

Abstract: The present invention provides a universal demodulation circuit, a load modulation circuit and associated method, and an associated power transfer system, all suitable for use in wireless power transfer. A power receiver with signal strength detection is also provided. Modulation of the impedance of the demodulation circuit is determinable by detecting the amplitudes of a first and a second electrical parameter, thereby demodulating data communicated by modulation of the impedance of the demodulation circuit. The modulation circuit has a communication modulator to modulate the impedance of the modulation circuit, to a predetermined minimum modulation depth, thereby to communicate data.

Abstract: The present invention provides an AC-DC converter and AC-DC conversion method for converting an AC input provided by a power transfer winding. The AC-DC converter includes a rectifying means for rectifying the AC input into a rectified output, and a control means for controlling the rectifying means based on a comparison between a reference signal and a voltage feedback signal, the voltage feedback signal being based on the rectified output.

Abstract: The present invention provides a universal demodulation circuit, a load modulation circuit and associated method, and an associated power transfer system, all suitable for use in wireless power transfer. A power receiver with signal strength detection is also provided. Modulation of the impedance of the demodulation circuit is determinable by detecting the amplitudes of a first and a second electrical parameter, thereby demodulating data communicated by modulation of the impedance of the demodulation circuit. The modulation circuit has a communication modulator to modulate the impedance of the modulation circuit, to a predetermined minimum modulation depth, thereby to communicate data.

Abstract: Various circuit configurations and topologies are provided for single and multi-phase, single-level or multi-level, full and half-bridge rectifiers in which diodes are replaced by combinations of voltage-controlled self-driven active switches, current-controlled self-driven active switches and inductors in order to reduce the effects of conduction loss in the diodes.