Abstract: This disclosure provides systems, methods and apparatus for tuning a wireless power transmitter. In one aspect an apparatus configured to wirelessly provide power to a load is provided. The apparatus includes a transmit circuit including a transmit coil. The transmit circuit is configured to wirelessly provide power to the load. The transmit coil is configured to resonate at a resonant frequency. The transmit circuit has a reactance. The apparatus further includes a detection circuit configured to detect a change in the resonant frequency while providing power to the load. The apparatus further includes a tuning circuit configured to adjust the reactance based on the change.

Abstract: This disclosure provides systems, methods and apparatus for increasing the efficiency of an amplifier when driven by a variable load. In one aspect a transmitter device is provided. The transmitter device includes a driver circuit characterized by an efficiency. The driver circuit is electrically connected to a transmit circuit characterized by an impedance. The transmitter device further includes a filter circuit electrically connected to the driver circuit and configured to modify the impedance to maintain the efficiency of the driver circuit at a level that is within 20% of a maximum efficiency of the driver circuit. The impedance is characterized by a complex impedance value that is within a range defined by a real first impedance value and a second real impedance value. A ratio of the first real impedance value to the second real impedance value is at least two to one.

Abstract: This disclosure provides systems, methods and apparatus for waking a wireless power transmitter from beacon mode. In one aspect a wireless power receiver apparatus is provided. The wireless power receiver apparatus includes a receive circuit comprising a receive coil. This receive circuit is coupled to a load. The receive circuit is configured to wirelessly receive power from a transmitter device at a first power level to power the load. The wireless power receiver apparatus further includes an adjustment circuit configured to be powered by using the wirelessly received power. The adjustment circuit is further configured to adjust a characteristic of the load using the wirelessly received power for a period of time to cause a detectable change in an operating characteristic of the transmitter device for the period of time.

Abstract: This disclosure provides systems, methods and apparatus for managing a temperature of a wireless power receiver. In one aspect a wireless power transmitter is provided. The wireless power transmitter includes a transmit circuit including a transmit coil. The transmit circuit is configured to wirelessly transmit power to a wireless power receiver. The wireless power transmitter further includes a communication circuit configured to receive information based on a temperature measurement of the wireless power receiver. The wireless power transmitter further includes a transmit controller circuit configured to adjust an operating point of power transfer based on the information.

Abstract: Embodiments of the subject invention relate to a method and apparatus for determining information regarding a load in a planar wireless power transfer system by extracting system operating parameters from one or more test points in the transmitter circuit. As shown in FIG. 1, a specific embodiment showing three test points in the transmitter circuit from which operating parameters can be extracted. The transmitter circuit is designed to produce a magnetic field, by driving the transmitter coil, which inductively couples to a receiver coil such that power is provided to a receiver. By extracting operating parameters from the transmitter circuit, the receiver does not need to incorporate sophisticated signal processing and can be manufactured with low cost.

Abstract: Exemplary embodiments are directed to wireless power communication. In one aspect a wireless power receiver configured to receive wireless power from a wireless power transmitter is provided. The wireless power receiver includes a switchable element configured to couple a receive coil to a ground voltage. The wireless power receiver further includes a detector coupled to the receive coil and configured to detect an externally generated pulse.

Abstract: Exemplary embodiments are directed to communication with a wireless power transmitter. A device may include an antenna for wirelessly transmitting a power carrier. The device may further include transmit circuitry coupled to the antenna and configured to transmit a data carrier at a frequency corresponding to at least one harmonic of the power carrier.

Abstract: Exemplary embodiments are directed to wireless power charging. A device may include at least one sensing element for measuring at least one parameter within a receiver configured to receive wirelessly transmitted power. The device may include a switching element configured to enable the receiver to convey energy to a load when the at least one parameter exceeds a threshold value.

Abstract: Exemplary embodiments are directed to a device include a parasitic coil for protection of the device. A device may include a first circuit configured to receive a first transmitted signal at an operational frequency. The device may also include a second circuit a second circuit configured to generate a field that opposes at least one of an undesirable portion of a wireless power field of the first transmitted signal and a portion of another wireless power field proximate the first circuit, the another wireless power field generated by a second transmitted signal at a non-operational frequency of the first circuit.

Abstract: Exemplary embodiments are directed to detection and validation of wirelessly chargeable devices positioned within a charging region of a wireless power transmitter. A device may include a wireless power transmitter configured detect a change in at least one parameter at the transmitter. The transmitter may further be configured to determine whether at least one valid chargeable device is positioned within a charging region of the transmitter upon detecting the change in the at least one parameter.

Abstract: Exemplary embodiments are directed to wireless power reception at a wireless power receiver. A receiver may include a coil comprising a plurality of loops. The receiver may further include a switching element coupled to the coil for selectively shorting at least one loop of the plurality.

Abstract: Exemplary embodiments are directed to resonant frequency tuning. A device may include a coil for transmitting wireless power.

Abstract: Exemplary embodiments are directed to control of field distribution of a wireless power transmitter. A transmitter may include a transmit antenna configured to generate a field. The transmitter may further include least one parasitic antenna proximate the transmit antenna and configured to modify a distribution of the generated field.

Abstract: Exemplary embodiments are directed to power distribution among a plurality of receivers. A method may include requesting at least one receiver of a plurality of receivers within a charging region of a transmitter to modify an associated load resistance to achieve a desired power distribution among the plurality of receivers. The method may further include requesting each receiver of the plurality of receivers to modify an associated load resistance to achieve a desired total impedance as seen by the transmitter while maintaining the desired power distribution among the plurality of receivers.

Abstract: Exemplary embodiments are directed to forward link signaling via transmitter detuning A method may include selectively detuning a circuit to adjust an amplitude of an associated transmit signal based on data to be transmitted. The method may also include selectively retuning the circuit to differently adjust the amplitude of the transmit signal based on the data to be transmitted.

Abstract: Exemplary embodiments are directed to detecting and limiting power transfer to non-compliant devices. A method may include detecting one or more non-compliant devices positioned within a charging region of a wireless power transmitter. The method may further include limiting an amount of power delivered to at least one of the one or more non-compliant devices.

Abstract: Exemplary embodiments are directed to reverse-link signaling via modification of an impedance on the receiver as detected by a transmitter. A method may include receiving a signal from a transmitter at a receiver unit. The method may further include adjusting an impedance detectable by the transmitter by modifying a load coupled with the receiver unit.

Abstract: Embodiments of the subject invention pertain to a method and apparatus for contactless power transfer. A specific embodiment relates to an impedance transformation network, a new class of load network for application to a contactless power system. Embodiments of the impedance transformation network enable a contactless power system to operate without encountering the common problems of: 1) over-voltage and/or under-voltage conditions; 2) over-power and/or under-power conditions; 3) power oscillations; and 4) high heat dissipation.

Abstract: Embodiments of the invention pertain to a method and apparatus for planar wireless power transfer where the receiver switches off and/or performs a duty cycle. In an embodiment, the switch can be used in a system that having a high voltage/current solid state switch, without having a high voltage control signal. An embodiment provides a switch that is capable of breaking, or greatly reducing, the connection of the receiver coil and the receiver circuitry in order to enable the receiver to decouple from the power transfer system. This embodiment can allow the transmitter to put out more power to other devices without providing power to the switched device. When the switch is used for a fully charged device, the switching can prevent or reduce damage to the fully charged device.

Abstract: Embodiments of the subject invention relate to a method and apparatus for determining information regarding a load in a planar wireless power transfer system by extracting system operating parameters from one or more test points in the transmitter circuit. As shown in FIG. 1, a specific embodiment showing three test points in the transmitter circuit from which operating parameters can be extracted. The transmitter circuit is designed to produce a magnetic field, by driving the transmitter coil, which inductively couples to a receiver coil such that power is provided to a receiver. By extracting operating parameters from the transmitter circuit, the receiver does not need to incorporate sophisticated signal processing and can be manufactured with low cost.