Abstract: Methods, systems, and devices for operating wireless power transfer systems. One aspect features a wireless energy transfer system that includes a transmitter, and a receiver. The transmitter has a transmitter-IMN and is configured to perform operations including performing a first comparison between a characteristic of a power of the transmitter and a target power. Adjusting, based on the first comparison, a reactance of the transmitter-IMN to adjust the power of the transmitter. The receiver has a receiver-IMN and is configured to perform operations including determining an efficiency of the wireless energy transfer system at a second time based on power data from the transmitter. Performing a second comparison between the efficiency at the second time and an efficiency of the wireless energy transfer system at a first time, the first time being prior to the second time. Adjusting, based on the second comparison, a reactance of the receiver-IMN.

Abstract: The disclosure features wireless power devices for receiving power from a wireless power source. The devices include a first plurality of magnetic material pieces of substantially planar shape arranged in a first plane, where the first plurality of magnetic material pieces have a first planar surface and a second planar surface. The devices include a device resonator comprising at least one wound conductor disposed on the first planar surface and a second plurality of magnetic material pieces in a second plane, where at least one of the second plurality of magnetic material pieces overlaps at least one of the first plurality of magnetic material pieces and where a separation between the first and second planes is less than 2 mm.

Abstract: A wireless power system for powering a television includes a source resonator, configured to generate an oscillating magnetic field, and at least one television component attached to at least one device resonator, wherein the at least one device resonator is configured to wirelessly receive power from the source resonator via the oscillating magnetic field when the distance between the source resonator and the at least one device resonator is more than 5 cm, and wherein at least one television component draws at least 10 Watts of power.

Abstract: A wireless power receiver is coupled to an impedance matching network, the impedance matching network having a first node and a second node. Coupled to the first node is a first branch having a first positive reactance and a second branch having a first negative reactance, wherein an absolute value of the first positive reactance is different from an absolute value of the first negative reactance, and coupled to the second node is a third branch having a second positive reactance and a fourth branch having a second negative reactance, wherein an absolute value of the second positive reactance is different from an absolute value of the second negative reactance.

Abstract: Described herein are improved configurations for a wireless power transfer. Described are methods and designs to reduce and manage heating and heat dissipation in resonator structures. Configuration and orientation of magnetic material as well as heat sinking material with respect to the dipole moment of the resonator is used to reduce and control thermal properties of the resonator structure and reduce the effects of heating on the performance of wireless power transfer.

Abstract: A wireless power system for powering a television includes a source resonator, configured to generate an oscillating magnetic field, and at least one television component attached to at least one device resonator, wherein the at least one device resonator is configured to wirelessly receive power from the source resonator via the oscillating magnetic field when the distance between the source resonator and the at least one device resonator is more than 5 cm, and wherein at least one television component draws at least 10 Watts of power.

Abstract: A wireless power receiver is coupled to an impedance matching network, the impedance matching network having a first node and a second node. Coupled to the first node is a first branch having a first positive reactance and a second branch having a first negative reactance, wherein an absolute value of the first positive reactance is different from an absolute value of the first negative reactance, and coupled to the second node is a third branch having a second positive reactance and a fourth branch having a second negative reactance, wherein an absolute value of the second positive reactance is different from an absolute value of the second negative reactance.

Abstract: Described herein are configurations for an integrated resonator-shield structure for wireless power transfer. In embodiments a conductor shield is used to shield the resonator from perturbing objects. In embodiments the conductor shield is used for a current return path for the conductors of the resonator. The resonator shield can be divided into separate conductor segments to tailor the current distributions in the conductor shield.

Abstract: A wireless power system for powering a television includes a source resonator, configured to generate an oscillating magnetic field, and at least one television component attached to at least one device resonator, wherein the at least one device resonator is configured to wirelessly receive power from the source resonator via the oscillating magnetic field when the distance between the source resonator and the at least one device resonator is more than 5 cm, and wherein at least one television component draws at least 10 Watts of power.

Abstract: The disclosure features apparatus, methods, and systems for wireless power transfer that include a power source featuring at least one resonator, a power receiver featuring at least one resonator, a first detector featuring one or more loops of conductive material and configured to generate an electrical signal based on a magnetic field between the power source and the power receiver, a second detector featuring conductive material, and control electronics coupled to the first and second detectors, where during operation, the control electronics are configured to measure the electrical signal of the first detector and compare the measured electrical signal of the first detector to baseline electrical information for the first detector to determine information about whether debris is positioned between the power source and the power receiver.

Abstract: A wireless power system for powering a television includes a source resonator, configured to generate an oscillating magnetic field, and at least one television component attached to at least one device resonator, wherein the at least one device resonator is configured to wirelessly receive power from the source resonator via the oscillating magnetic field when the distance between the source resonator and the at least one device resonator is more than 5 cm, and wherein at least one television component draws at least 10 Watts of power.

Abstract: Disclosed is an apparatus for use in wireless energy transfer, which includes a first resonator structure configured to transfer energy non-radiatively with a second resonator structure over a distance greater than a characteristic size of the second resonator structure. The non-radiative energy transfer is mediated by a coupling of a resonant field evanescent tail of the first resonator structure and a resonant field evanescent tail of the second resonator structure.

Abstract: Methods, systems, and devices for operating wireless power transfer systems. One aspect features a wireless energy transfer system that includes a transmitter, and a receiver. The transmitter has a transmitter-IMN and is configured to perform operations including performing a first comparison between a characteristic of a power of the transmitter and a target power. Adjusting, based on the first comparison, a reactance of the transmitter-IMN to adjust the power of the transmitter. The receiver has a receiver-IMN and is configured to perform operations including determining an efficiency of the wireless energy transfer system at a second time based on power data from the transmitter. Performing a second comparison between the efficiency at the second time and an efficiency of the wireless energy transfer system at a first time, the first time being prior to the second time. Adjusting, based on the second comparison, a reactance of the receiver-IMN.

Abstract: Techniques herein provide wireless energy transfer to audio devices such as headphones, headsets, hearing aids, and the like. Audio devices are integrated with a device resonator. The device resonator may be positioned and oriented to reduce interaction with lossy or sensitive components of the audio device. A repeater resonator and/or a source resonator is integrated into a headrest of a seat or a chair providing continuous power to the headphones while in use. The audio devices may be recharged wirelessly when positioned near source resonators that may be embedded in pads, tables, carrying cases, cups, and the like.

Abstract: A wireless power transmission system (100) includes a conductive waveguide (110) at least partially filled with a dielectric material (115), the waveguide extending along a first direction (e.g., z-axis) from a first end (111a) to an opposing end (111b) thereof, the waveguide having a bottom face (112), a top face (114) and a pair of side faces (116a, 116b) that together form a substantially rectangular cross-section of the waveguide, the top face having a plurality of slots (118) oriented substantially orthogonal to the first direction and distributed between the first end and the opposing end, the slots separated from each other by a first distance (l1) measured along the first direction.

Abstract: The disclosure features apparatus, methods, and systems for wireless power transfer that include a power source featuring at least one resonator, a power receiver featuring at least one resonator, a first detector featuring one or more loops of conductive material and configured to generate an electrical signal based on a magnetic field between the power source and the power receiver, a second detector featuring conductive material, and control electronics coupled to the first and second detectors, where during operation, the control electronics are configured to measure the electrical signal of the first detector and compare the measured electrical signal of the first detector to baseline electrical information for the first detector to determine information about whether debris is positioned between the power source and the power receiver.

Abstract: In a first aspect, the disclosure features apparatuses for wireless power transfer, the apparatuses including a plurality of magnetic elements joined together to form a magnetic component extending in a plane, where discontinuities in the magnetic component between adjacent magnetic elements define gaps in the magnetic component, a coil including one or more loops of conductive material positioned, at least in part, on a first side of the plane. The apparatuses include a conductive shield positioned on a second side of the plane and which includes one or more openings positioned relative to the gaps.

Abstract: A resonator connector for a wireless power transfer system includes: one or more conducting materials to carry electricity between two or more electromagnetic resonators; a first plug coupled with the one or more conducting materials; a second plug coupled with the one or more conducting materials; and an impedance module coupled with the one or more conducting materials, the impedance module including an impedance matching network; wherein the impedance module is configurable to adjust electrical properties of the one or more conducting materials, using the impedance matching network, when the resonator connector electrically couples together the two or more electromagnetic resonators of the wireless power transfer system including at least three electromagnetic resonators, so as to improve power transfer efficiency among the at least three electromagnetic resonators of the wireless power transfer system, the at least three electromagnetic resonators including the two or more electromagnetic resonators.

Abstract: Methods, systems, and devices for controlling a variable capacitor. One aspect features a variable capacitance device that includes a capacitor, a first transistor, a second transistor, and control circuitry. The control circuitry is configured to adjust an effective capacitance of the capacitor by performing operations including detecting a zero-crossing of an input current at a first time. Switching off the first transistor. Estimating a first delay period for switching the first transistor on when a voltage across the capacitor is zero. Switching on the first transistor after the first delay period from the first time. Detecting a zero-crossing of the input current at a second time. Switching off the second transistor. Estimating a second delay period for switching the second transistor on when a voltage across the capacitor is zero. Switching on the second transistor after the second delay period from the second time.

Abstract: Disclosed is an apparatus for use in wireless energy transfer, which includes a first resonator structure configured to transfer energy non-radiatively with a second resonator structure over a distance greater than a characteristic size of the second resonator structure. The non-radiative energy transfer is mediated by a coupling of a resonant field evanescent tail of the first resonator structure and a resonant field evanescent tail of the second resonator structure.