Abstract: Systems, methods and apparatus are disclosed for filtering. In one aspect a power cable apparatus is provided. The apparatus includes a cable portion. The apparatus further includes a first connector portion coupled to a first end of the cable portion. The apparatus further includes a second connector portion coupled to a second end of the cable portion opposite the first end. The apparatus further includes a filter circuit integrated within the second the connector portion, the filter circuit configured to attenuate emissions at an operating frequency of the electronic device.

Abstract: Exemplary embodiments are directed to controlling impedance. A wireless power transmitter for controlling impedance comprises a transmit circuit configured to wirelessly transmit power to a plurality of receivers, each having a load resistance, within a charging region of the transmit circuit. The transmitter also comprises a controller configured to request each receiver of the plurality of receivers to adjust its load resistance to a value that achieves a target total impedance as presented to the controller.

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: This disclosure provides systems, methods and apparatus for reducing harmonic emissions. One aspect of the disclosure provides a transmitter apparatus. The transmitter apparatus includes a driver circuit characterized by an efficiency and a power output level. The driver circuit further includes a filter circuit electrically connected to the driver circuit and configured to modify the impedance of the transmit circuit to maintain the efficiency of the driver circuit at a level that is within 20% of a maximum efficiency of the driver circuit when the impedance is within the complex impedance range. The filter circuit is further configured to maintain a substantially constant power output level irrespective of the reactive variations within the complex impedance range. The filter circuit is further configured to maintain a substantially linear relationship between the power output level and the resistive variations within the impedance range.

Abstract: An embodiment of a system for wirelessly charging a wrist-worn device may include a radio frequency (RF) charging energy generating element, and an antenna configured to radiate the RF charging energy, the antenna comprising a first coil and a second coil, the first coil and the second coil each comprising a plurality of windings, the windings of the first coil being wound in a direction opposite the direction of the windings of the second coil. An embodiment of a wrist-worn charge-receiving device may include an antenna coil adapted to receive radio frequency (RF) charging energy, the antenna coil comprising non-uniform windings; and a rechargeable power source coupled to the antenna coil, the antenna coil adapted to provide the RF charging energy to the rechargeable power source.

Abstract: This disclosure provides systems, methods and apparatus for forward link communication in wireless power systems. One aspect of the disclosure provides a wireless charging device for providing wireless power to a receiving device. The wireless charging device includes a primary transmit antenna configured to generate a wireless power field. The device further includes a parasitic antenna configured to selectively adjust a coupling between the primary transmit antenna and the receiving device. The device further includes a controller configured to control the selective adjustment of the parasitic antenna so as to communicate with the receiving device.

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: An apparatus for wirelessly receiving power comprises a battery at least partially covered by magnetic material and a radio frequency (RF) charge energy receiving antenna surrounding the magnetic material and electrically coupled to the battery through a circuit card assembly (CCA).

Abstract: This disclosure provides systems, methods and apparatus for decoupling multiple wireless charging transmitters. In one aspect, a device is configured to transmit wireless power to a first receiver. The device includes a first driver coil and a second driver coil. The device further includes a common reactance element connected to the first driver coil and the second driver coil. The reactance element is configured to at least partially cancel mutual inductance between the first driver coil and the second driver coil.

Abstract: An apparatus for wireless charging using radio frequency (RF) energy includes a charger coil configured to produce RF charging energy as a magnetic field, the charger coil located proximate to a magnetic material and a metal material, the magnetic material and the metal material located to attenuate the magnetic field generated by the charger coil beyond a plane defined by a major surface of the magnetic material and the metal material, a first portion of the magnetic material underlying the charger coil and a second portion of magnetic material overlying the charger coil.

Abstract: This disclosure provides systems, methods, and apparatus for transferring power wirelessly via a wireless power transmitter. In one aspect, the transmitter comprises a first circuit configured to generate a first signal, where the first circuit includes a first inductor. The transmitter further comprises a second circuit configured to generate a second signal out of phase with the first signal. The second circuit includes a second inductor inductively coupled with the first inductor. The first inductor and the second inductor may have a leakage inductance of at least a minimum value so as to not produce a substantially square waveform at an output of the first circuit and an output of the second circuit. The transmitter further comprises a filter circuit configured to filter the first signal and the second signal.

Abstract: Systems and methods for sensing reverse link signaling are described herein. In one aspect, an apparatus for wireless transmission includes a push-pull driver circuit, coil, and sensor. The push-pull driver circuit is configured to generate a signal. The coil is electrically coupled to the push-pull driver circuit, and the coil is configured to receive the signal from the push-pull driver circuit and wirelessly transmit the signal to a receiver. The sensor is electrically coupled to a virtual alternating current (AC) ground of the push-pull driver circuit or the coil. The sensor is configured to sense a shift in voltage at the virtual AC ground where the shift in voltage is representative of a change of an input impedance of the receiver.

Abstract: An apparatus for wireless charging using radio frequency (RF) energy includes a first charger portion having first and second charging areas. The first and second charging areas are located in a common plane, each having at least one coil for wirelessly charging a charge-receiving device placed in proximity thereto. The coils include respective windings, which are wound in opposing directions, each coil being connected in series, each coil configured to charge at least one charge-receiving device. A second charger portion has a third charging area having at least one coil including a winding for wirelessly charging a charge-receiving device placed in proximity to the third charging area, the coil in the third charging area being connected in series with the coils in the first and second charging areas, the third charging area located in a plane that is orthogonal to the plane of the first and second charging areas.

Abstract: This disclosure provides systems, methods and apparatus for tuning a transmit antenna for operation in a plurality of frequency bands. In one aspect, a transmitting antenna system is provided. The transmitting antenna system includes an active transmit antenna and a tunable passive antenna. The active antenna is configured to transmit a field over a plurality of operating frequencies. The passive antenna is configured to transmit a field over at least two frequencies of the plurality of operating frequencies. In one aspect, the tunable passive antenna includes a network of a plurality of reactive elements. In another aspect, the plurality of operating frequencies is selected from a set including a charging frequency, an NFC frequency, and a communication frequency.

Abstract: This disclosure provides systems, methods, and apparatus for filtering of a rectifier in a wireless power receiver. In one aspect a wireless power receiver is provided. The wireless power receiver includes a rectifier circuit configured to provide direct-current (DC) based at least in part on a time-varying voltage generated via a wireless field provided from a wireless power transmitter. The wireless power receiver further includes a band-stop filter circuit configured to filter an output of the rectifier circuit and electrically isolate a capacitor from the rectifier circuit at an operating frequency.

Abstract: This disclosure provides systems, methods, and apparatus for filtering of a rectifier in a wireless power receiver. In one aspect a wireless power receiver apparatus is provided. The receiver apparatus includes a coil circuit configured to wirelessly receive power via a wireless field. The receiver apparatus further includes a rectifier circuit configured to provide direct-current (DC) based at least in part on the received power. The receiver apparatus further includes a first filter circuit electrically connected between the coil and the rectifier circuit and configured to reduce emissions from the rectifier circuit and configured to maintain a first impedance presented by the rectifier circuit substantially equal to a second impedance presented to the coil circuit. The receiver apparatus further includes a band-stop filter circuit configured to electrically isolate emissions from the rectifier circuit.

Abstract: Embodiments are directed to detecting and identifying a type of a wireless power device in a wireless power transfer field. According to one aspect, systems and methods are disclosed which describe limiting power transfer to non-compliant devices and detection of undesired power absorbers, such as metal objects, in a wireless power system. A method may include detecting one or more non-compliant devices and/or undesired wireless power absorbers positioned within a charging region of a wireless power transmitter. The method may further include limiting an amount of power transmitted by a transmitter in response to the detection, or reducing the amount of power received by the non-compliant device.

Abstract: Systems, methods and apparatus are disclosed for signaling between wireless power transmitters and receivers. In one aspect a wireless power receiver is disclosed. The wireless power receiver includes an antenna circuit characterized by an impedance. The antenna circuit is configured to wirelessly receive power for powering or charging a load. The wireless power receiver further includes an impedance adjustment circuit configured to communicate multi-level signaling data values to a wireless power transmitter coupled to the receiver. The wireless power transmitter includes a controller configured to receive a signal indicative of a change in receiver impedance and determine the multi-level signaling data values based on the detected change.

Abstract: This disclosure provides systems, methods and apparatus for reducing harmonic emissions. One aspect of the disclosure provides a transmitter apparatus. The transmitter apparatus includes a transmit circuit having an impedance determined by a complex impedance value. The transmitter apparatus further includes a driver circuit coupled to the transmit circuit. The transmitter apparatus further includes a first filter circuit coupled between the driver circuit and a power source. The first filter circuit is configured to substantially isolate emissions presented by the driver circuit to the power source. The transmitter apparatus further includes a second filter circuit coupled between the driver circuit and the transmit circuit and configured to reduce emissions presented by the transmit circuit.