Abstract: An apparatus for receiving wireless power is provided. The apparatus a communication circuit configured to transmit a first indication of a first wireless charging category associated with the apparatus. The communication circuit is further configured to receive an indication of a wireless charging class of a power transmit unit (PTU). The communication circuit is further configured to transmit a second indication of a second wireless charging category associated with the apparatus based on the wireless charging class of the PTU being compatible with a higher wireless charging category than the first wireless charging category. The apparatus further comprises a coupler configured to receive a level of wireless power corresponding to the second wireless charging category. The higher wireless charging category indicates an ability to receive a greater amount of wireless power than the first wireless charging category.

Abstract: Certain aspects of the present disclosure are generally directed to apparatus and techniques for wireless charging. One example apparatus generally includes a plurality of inductive elements and signal generation circuitry coupled to the plurality of inductive elements and configured to generate a plurality of signals, where at least two signals of the plurality of signals have different magnitudes. In certain aspects, the signal generation circuitry is configured to drive the plurality of inductive elements using the plurality of signals, where at least one first inductive element of the plurality of inductive elements is driven using at least one first signal of the plurality of signals having a first phase and at least one second inductive element of the plurality of inductive elements is driven using at least one second signal of the plurality of signals having a second phase different from the first phase.

Abstract: Techniques for reducing reflected reactance in a wireless power transfer system are provided. An example apparatus includes a resonant network including a variable reactance element, such that the resonant network is configured to resonant when the variable reactance element is at a resonant reactance value, a control circuit operably coupled to the variable reactance element and configured to determine a first reactance value and a second reactance value, such that an output of the PRU is the desired output when the variable reactance element is either the first reactance value or the second reactance value, and the first reactance value is below the resonant reactance value and the second reactance value is above the resonant reactance value, determine an indication of a source reactance associated with a wireless power source, and adjust the variable reactance element to either the first reactance value or the second reactance value based on the indication of the source reactance.

Abstract: An electronic apparatus may include an electrically conductive body configured to magnetically couple to a first magnetic field. A first tuning element may be connected to the electrically conductive body. An electrically conductive coil may be wound about an opening defined by the electrically conductive body, and configured to magnetically couple to a second magnetic field.

Abstract: An apparatus may include an electrically conductive body to magnetically couple to a first magnetic field. A first tuning element may be connected to the electrically conductive body. An electrically conductive coil may be wound about an opening in the electrically conductive body, and configured to magnetically couple to a second magnetic field.

Abstract: Certain aspects of the present disclosure relate to methods and apparatus for detecting, by a wireless power transmitter, an over voltage protection at a wireless power receiver. Certain aspects of the present disclosure provide a wireless power transmitter. The wireless power transmitter includes a resonator configured to generate a wireless field for wirelessly transferring power to a wireless power receiver. The wireless power transmitter further includes an impedance detector configured to measure an impedance of the resonator. The wireless power transmitter further includes a controller configured to detect operation of an over voltage protection mode of the wireless power receiver based on a frequency of change in impedance as measured by the impedance detector.

Abstract: Certain aspects of the present disclosure are generally directed to apparatus and techniques for wireless charging. One example apparatus generally includes a plurality of inductive elements and signal generation circuitry coupled to the plurality of inductive elements and configured to generate a plurality of signals, where at least two signals of the plurality of signals have different magnitudes. In certain aspects, the signal generation circuitry is configured to drive the plurality of inductive elements using the plurality of signals, where at least one first inductive element of the plurality of inductive elements is driven using at least one first signal of the plurality of signals having a first phase and at least one second inductive element of the plurality of inductive elements is driven using at least one second signal of the plurality of signals having a second phase different from the first phase.

Abstract: Disclosed are methods, devices, systems, apparatus, media, and other implementations, including a method for wireless power transfer that includes operating a wireless power receiver in a default protection state in which charging or powering of a load coupled to the wireless power receiver is inhibited except upon detection of one or more safety charging conditions for safely charging the wireless power receiver, determining that a safety charging condition, of the one or more safety charging conditions, is met, and operating the wireless power receiver in a charging state at least in part in response to determining that the safety charging condition, of the one or more safety conditions, is met, with the wireless power receiver powering or charging the load while in the charging state and receiving power.

Abstract: An aspect of this disclosure is an apparatus for transmitting power wirelessly. The apparatus comprises a detection circuit and a processor. The apparatus also includes a power amplifier driving an antenna circuit of flexible antenna(s) configured for wireless power transfer. The processor determines that at least one measured variable of the power amplifier falls outside of a corresponding threshold range, indicative of a deformation of a physical shape of one of the flexible antennas or indicative of misalignment of the flexible antennas from a power receiver. The processor further commands the power amplifier to transition to a first power mode from a second power mode based on the determination that at least one of the measured variables falls outside of the corresponding threshold range. The antenna circuit in the first power mode transmits power at a power level less than the power level in the second power mode.

Abstract: Systems and methods for wirelessly transferring power via magnetic field in a wireless power transfer system. A plurality of coils are placed at different locations around a body and configured to generate respective magnetic fields over different portions of the body to charge a chargeable device implanted within the body. A time division scheme is used such that no portion of the body experiences an average SAR over time that exceeds a designated SAR limit.

Abstract: A wireless charging device includes: a base configured to be worn by a user; and a coil attached to the base and comprising an electrically conductive material shaped to produce a magnetic field to convey power wirelessly to a receiver in response to receiving power, the coil including multiple turns each having a turn length with at least one of the multiple turns having an adjustable turn length, the multiple turns being disposed along a common axis such that each of the multiple turns is disposed around the axis for the respective turn length of the turn.

Abstract: The present disclosure describes a power receiving unit for charging while in pre-overvoltage protection. In some aspects, reduced operation of an electronic implant device is initiated before resorting to overvoltage protection. In aspects, the electronic implant device has a power receiving unit capable of receiving power wirelessly from a wireless power transmitter. The power receiving unit can also detect an induced voltage and trigger pre-overvoltage protection when the detected voltage reaches a pre-overvoltage protection threshold. Additionally, a power management integrated circuit (PMIC) of the electronic implant device draws power from the power receiving unit to carry out corresponding functionality. The PMIC also obtains an indication when the detected voltage reaches the pre-overvoltage protection threshold. Based on the indication, the PMIC may reduce the power it draws from the power receiving unit to a predefined, reduced level instead of a normal operating level.

Abstract: Certain aspects of the present disclosure relate to methods and apparatus for detecting, by a wireless power transmitter, an over voltage protection at a wireless power receiver. Certain aspects of the present disclosure provide a wireless power transmitter. The wireless power transmitter includes a resonator configured to generate a wireless field for wirelessly transferring power to a wireless power receiver. The wireless power transmitter further includes an impedance detector configured to measure an impedance of the resonator. The wireless power transmitter further includes a controller configured to detect operation of an over voltage protection mode of the wireless power receiver based on a frequency of change in impedance as measured by the impedance detector.

Abstract: A wireless-power coupling system includes: a first power coupler comprising a first coil, the first coil comprising a first electrically-conductive loop; a second power coupler comprising a second coil, the second coil comprising a second electrically-conductive loop; and a third power coupler comprising a third coil, the third coil comprising a third electrically-conductive loop; where the first electrically-conductive loop and the second electrically-conductive loop are non-parallel relative to each other and overlap each other at a first plurality of locations of the first electrically-conductive loop; and where the first electrically-conductive loop and the third electrically-conductive loop are non-parallel relative to each other and overlap each other at a second plurality of locations of the first electrically-conductive loop, the first plurality of locations being distinct from the second plurality of locations.

Abstract: This invention describes a method and apparatus for providing wireless power. The methods and systems disclosed consist of a first coil having at least one loop forming an inner area inside boundaries of the at least one loop and an outer area outside the boundaries of the at least one loop, the first coil configured to generate a first alternating magnetic field for charging or powering a wireless power device, the first alternating magnetic field having a first magnetic field component with a first phase in the inner area, the first alternating magnetic field also having a second magnetic field component with a second phase in the outer area, and the second phase different from the first phase. In some aspects, the methods and systems comprise a second coil comprising a portion within the outer area, the second coil configured to reduce a magnitude of the second magnetic field component.

Abstract: Certain aspects of the present disclosure generally relate to methods and apparatus for wirelessly charging a device having a wireless power receiver with a dead battery. One example method for safely wirelessly charging an implantable device, with an apparatus, generally includes determining that the implantable device has a dead battery; based on the determination, wirelessly transmitting power from the apparatus at an initial level for a first interval; checking for a first signal received from the implantable device during or at an end of the first interval or a period associated with the initial level; and if no first signal is received from the implantable device, increasing the transmitted power to a higher level for a second interval.

Abstract: Certain aspects of the present disclosure relate to methods and apparatus for power dissipation control for a wireless power receiver. Certain aspects of the present disclosure provide a wireless power receiver. The wireless power receiver includes a resonator including an inductor and a capacitor. The resonator is configured to couple to a wireless field. The wireless field induces a voltage in the resonator. The capacitor is coupled to the inductor. The capacitor is configured to at least one of shunt tune or series tune the resonator. The wireless power receiver further includes a control circuit configured to at least one of selectively couple the capacitor to the inductor or adjust a capacitance of the capacitor based on at least one of a temperature near the wireless power receiver or an electrical characteristic of a thermally conductive path between the wireless power receiver and a surrounding thermal environment.

Abstract: Certain aspects of the present disclosure relate to methods and apparatus for hybrid rectification for wireless power. Certain aspects of the present disclosure provide a wireless power receiver. The wireless power receiver includes a resonator configured to couple to a wireless field. The wireless field induces a voltage in the resonator. The wireless power receiver further includes an active rectifier comprising one or more switches. The wireless power receiver further includes a passive rectifier comprising one or more diodes. The wireless power receiver further includes a switch selectively coupling the active rectifier and the passive rectifier to the resonator.

Abstract: An electronic apparatus may include an electrically conductive body configured to magnetically couple to a first magnetic field. A first tuning element may be connected to the electrically conductive body. An electrically conductive coil may be wound about an opening defined by the electrically conductive body, and configured to magnetically couple to a second magnetic field.

Abstract: An apparatus may include an electrically conductive body to magnetically couple to a first magnetic field. A first tuning element may be connected to the electrically conductive body. An electrically conductive coil may be wound about an opening in the electrically conductive body, and configured to magnetically couple to a second magnetic field.