Abstract: Techniques are described for managing operations of a wireless-power-transmitting device, capable of operating in multiple radio-frequency (RF) bands. An example integrated circuit includes (i) an interface to couple with a power amplifier, (ii) an encryption block configured to authorize wireless-power-receiving devices, and (iii) a processing subsystem. The processing subsystem is configured to determine, using the encryption block, that multiple wireless-power-receiving devices are authorized to receive wirelessly-delivered power at multiple distinct frequencies. And after determining that the multiple wireless-power-receiving devices are authorized to receive wirelessly-delivered power, the processing subsystem provides multiple input signals, including signals having different respective frequencies, to the power amplifiers via the interface, to be amplified such that, when the amplified signals are sent to antennas, the antennas transmit RF signals to multiple receivers at multiple frequencies.

Abstract: A wireless power receiving system includes two or more electrically small antenna arms and a common antenna ground. The two or more electrically small antenna arms are connected to the same common antenna ground and are close enough to one another to be strongly coupled. In some embodiments, the two or more electrically small antenna arms are tuned to the same functional frequency so that they load one another to create self-resonance. The wireless power receiving system receives the transmitted wireless power wave emitting from a wireless power transmitter without added lossy matching components.

Abstract: An example method performed by a wireless-power-transmitting device that includes an antenna array is provided. The method includes radiating electromagnetic waves that form a maximum power level at a first distance away from the antenna array. Moreover, a power level of the radiated electromagnetic waves decreases, relative to the maximum power level, by at least a predefined amount at a predefined radial distance away from the maximum power level. In some embodiments, the method also includes detecting a location of a wireless-power-receiving device, whereby the location of the wireless-power-receiving device is further from the antenna array than a location of the maximum power level.

Abstract: A method of charging multiple receivers, the method includes: (i) receiving, via the communication radio, first data that allows the transmitter to determine a locations for a first receiver and a second receiver, (ii) determining waveform features used to transmit wireless power waves focused at the location of the first receiver, (iii) determining waveform features used to transmit wireless power waves focused at the location of the second receiver, (iv) causing a first subset of antennas to transmit wireless-power waves having the first waveform features to create focused energy at the location of the first receiver and (v) causing a second subset of antennas to transmit wireless-power waves having the second waveform features to create focused energy at the second location of the second receiver, where transmitting the wireless-power waves having the first waveform features occurs while transmitting the wireless-power waves having the second waveform features.

Abstract: An exemplary embodiment of secure wireless transmission of power using unidirectional communication signals from a wireless-power-receiving device. The method includes, receiving, from a wireless-power-transmitting device that includes a first communications radio, a first wireless-power-transmission signal at a wireless-power-receiving device that includes a second communications radio. In response to receiving the first wireless-power-transmission signal: broadcasting, via the second communications radio of the wireless-power-receiving device and without establishing a communications channel between the first and second communications radios, a data packet, the data packet including information identifying (i) at least one power requirement of a power source of the wireless-power-receiving device (ii) an amount of power received by the wireless-power-receiving device from the first wireless-power-transmission signal.

Abstract: A method includes receiving a wireless communication signal indicating that a receiver is within a wireless-power-transmission range of a transmitter. In response to the receiving, the method further includes transmitting a plurality of radio frequency (RF) test signals using at least two test phases for a respective antenna. The method further includes receiving information identifying a first amount of power delivered to the receiver by a first RF test signal transmitted at a first of the at least two test phases, receiving information identifying a second amount of power delivered to the receiver by a second RF test signal transmitted at a second of the at least two test phases, and determining, based on the first and second amounts of power, an optimal phase for the respective antenna.

Abstract: A near-field antenna is provided, which includes: a first dipole antenna, formed along a first axis, having a first meandering shape and a second dipole antenna, formed along a second axis different from the first axis, having a second meandering shape. The antenna also includes (i) a power amplifier configured to feed electromagnetic signals to at least one of the first and second dipole antennas, (ii) an impedance-adjusting component configured to adjust an impedance of at least one of the first and second dipole antennas, and (iii) switch circuitry configured to switchably couple the first dipole antenna, the power amplifier, the second dipole antenna, and the impedance-adjusting component.

Abstract: An antenna for receiving wireless power from a transmitter is provided. The antenna includes multiple antenna elements, coupled to an electronic device, configured to receive radio-frequency (RF) power waves from the transmitter, each antenna element being adjacent to at least one other antenna element. Furthermore, the multiple antenna elements are arranged so that an efficiency of reception of the RF power waves by the antenna elements remains above a predetermined threshold efficiency when a human hand is in contact with the electronic device, the predetermined threshold efficiency being at least 50%. Lastly, at least one antenna element is coupled to conversion circuitry, which is configured to (i) convert energy from the received RF power waves into usable power and (ii) provide the usable power to the electronic device for powering or charging of the electronic device.

Abstract: A method includes receiving an indication that a wireless-power receiver is located within one meter of a wireless-power transmission system and is authorized to receive wirelessly-delivered power from a wireless-power transmission system. The method includes, in response to receiving the indication, selecting a power level at which to amplify a radio frequency (RF) signal using a power amplifier (PA). In accordance with a determination that transmitting the RF signal to the wireless-power receiver would satisfy safety thresholds, the method includes instructing the PA to amplify the RF signal using the power level to create an amplified RF signal, and providing the amplified RF signal to the one or more antennas. The one or more antennas are caused to, upon receiving the amplified RF signal, radiate RF energy that is focused within an operating area that includes the wireless-power receiver while forgoing any active beamforming control.

Abstract: A wireless-power receiver includes an antenna coupled to a rectifier, and a depletion-mode switch coupled to the rectifier. The depletion-mode switch can create an impedance mismatch or an impedance match between the rectifier and the antenna. While the depletion-mode switch is in a default-closed state, it creates an impedance mismatch between the rectifier and the antenna. A first amount of alternating current received by the antenna as radio frequency (RF) signals is reflected away from the rectifier's input due to the impedance mismatch. A second amount of the alternating current causes the depletion-mode switch to begin transitioning to an open state, creating an impedance match between the rectifier and the antenna. While the depletion-mode switch is in the open state, creating an impedance match between the rectifier and the antenna, alternating current received by the antenna flows through the rectifier's input to be converted into direct current.

Abstract: An example method is provided for detecting and classifying foreign objects, performed at a computer system having one or more processors and memory storing one or more programs configured for execution by the one or more processors. The method includes obtaining a plurality of electrical measurements while a wireless-power-transmitting antenna is transmitting different power beacons. The method also includes forming a feature vector according to the plurality of electrical measurements. The method further includes detecting a presence of one or more foreign objects prior to transmitting wireless power to one or more wireless power receivers by inputting the feature vector to trained one or more classifiers, wherein each classifier is a machine-learning model trained to detect foreign objects distinct from the one or more wireless power receivers.

Abstract: An example system charges an electronic device using wirelessly transmitted radio-frequency power (RF) waves. The system includes the electronic device with one or more movable arms. At least one movable arm includes a receiving antenna element. The system further includes a charging pad that includes a housing. The housing includes at least one guiding contour on a surface that is configured for align a position of the electronic device on the surface of the housing. The charging pad further includes transmitting antenna elements that are selectively activated to transmit radio-frequency power waves to the receiving antenna element of the electronic device. The system also includes a transmitter controller integrated circuit (IC) configured to selectively activate a respective transmitting antenna element of the transmitting antenna elements. Activating the respective transmitting antenna element causes transmission of the radio-frequency power waves to the receiving antenna element of the electronic device.

Abstract: A method of wireless power transmission is performed at a wireless-power-transmitting device having one or more antennas configured to transmit wireless-power signals, one or more processors, and a wireless data transceiver.

Abstract: An example integrated circuit includes: (i) a processing subsystem configured to control operation of the integrated circuit, (ii) a waveform generator, operatively coupled to the processing subsystem, configured to generate radio frequency (RF) power transmission signals using an input current, (iii) a first digital interface that couples the integrated circuit with a plurality of power amplifiers that are external to the integrated circuit, and (iv) a second digital interface, distinct from the first digital interface, that couples the integrated circuit with a wireless communication component that is external to the integrated circuit. The processing subsystem is configured to: receive, via the second digital interface, an indication that a receiver is within transmission range of a transmitting device controlled by the circuit, and in response to receiving the indication: provide, via the first digital interface, the RF power transmission signals to at least one of the plurality of power amplifiers.

Abstract: A method of fabricating a near-field antenna for transmitting radio frequency (RF) power transmission signals includes selecting a set of dimensions for one or more cutouts to be defined through a conductive plate of the near-field antenna. The conductive plate has opposing first and second planar surfaces. The method includes forming the one or more cutouts through the first and second surfaces of the conductive plate in a predefined arrangement. Each of the one or more cutouts has the set of dimensions. The method includes coupling an insulator to the first surface of the conductive plate, and coupling a feed element to the insulator.

Abstract: Embodiments of wireless power receivers are disclosed herein. For example, a wireless power receiver comprises an antenna configured to: receive radio frequency (RF) waves from a transmitter; and convert energy from the RF waves into alternating current. The wireless power receiver also includes a rectifier coupled to the at least one antenna that rectifies the alternating current into a direct current; and a charger, coupled to the rectifier, the charger configured to: receive the direct current; and control, via circuitry that is coupled with the charger, distribution of current using conduction paths: (i) to a load, and (ii) to and from at least one storage element coupled with the charger. In some embodiments, the circuitry is configured to select the one of the conduction paths based on: a respective power requirement of the load, a respective power requirement of the at least one storage element, and the direct current.

Abstract: The wireless power receiver includes at least one wire of a sound-producing device. The at least one wire configured for both conveying sound signals or securing at least part of the sound-producing device to a user, and receiving power waves. The wireless power receiver also includes power harvesting circuitry coupled with the at least one wire and a power source of an electronic device, like a battery. The power harvesting circuitry is configured to isolate the received power waves from the conveyed sound signals, convert the received power waves to usable energy, and provide the usable energy to the power source of the electronic device.

Abstract: An example wireless power transmitter includes: (i) a ground plate, (ii) a conductive wire offset from the ground plate, the conductive wire forming a loop antenna that is configured to radiate an RF signal for wirelessly powering a receiver device, (iii) a plurality of feed elements extending from the ground plate to the conductive wire, each feed element being connected to the conductive wire at a different position on the conductive wire, and (iv) a power amplifier connected to one or more feed elements of the plurality of feed elements. The power amplifier is configured to selectively feed the RF signal to a respective feed element of the one or more feed elements based on a location of the receiver device relative to the plurality of feed elements.