Abstract: An example method is performed at a near-field charging pad with a processor, a power-transferring element, a signature-signal-receiving circuit, and the processor of the near-field charging pad is in communication with a data source that includes predefined signature signals that each identify one of (i) a wireless power receiver, (ii) an object other than a wireless power receiver, and (iii) a combination of a wireless power receiver and an object other than a wireless power receiver. The method includes: after sending a plurality of test radio frequency (RF) power transmission signals, detecting, using the signature-signal-receiving circuit, respective amounts of reflected power; generating, based on variations in the respective amounts of reflected power, a signature signal; and determining whether (i) an authorized wireless power receiver is present on the near-field charging pad and/or (ii) an object other than a wireless power receiver is present on the near-field charging pad.

Abstract: Methods and devices for surveying for active and inactive power receivers within a wireless-power coverage area are described. A method includes causing performance of a survey looking for active power receivers within a wireless-power coverage area using communication radio(s). Information is received from an active power receiver and transmission of RF signals is caused to energize inactive power receivers using a power-transmission antenna. A first RF signal is transmitted using a first value for a transmission characteristic, and a second RF signal is transmitted using a second value for the transmission characteristic. Additional information is received from a first energized power receiver and further information from a second energized power receiver. Two or more frequency bands are identified for radio-frequency wireless-power transmissions by a wireless-power transmitting device within the wireless-power coverage area based on the information, the additional information, and the further information.

Abstract: An example method is performed at a near-field charging pad with a processor, a power-transferring element, a signature-signal-receiving circuit, and the processor of the near-field charging pad is in communication with a data source that includes predefined signature signals that each identify one of (i) a wireless power receiver, (ii) an object other than a wireless power receiver, and (iii) a combination of a wireless power receiver and an object other than a wireless power receiver. The method includes: after sending a plurality of test radio frequency (RF) power transmission signals, detecting, using the signature-signal-receiving circuit, respective amounts of reflected power; generating, based on variations in the respective amounts of reflected power, a signature signal; and determining whether (i) an authorized wireless power receiver is present on the near-field charging pad and/or (ii) an object other than a wireless power receiver is present on the near-field charging pad.

Abstract: A method includes selecting a power level from among available power levels at which to amplify a radio frequency (RF) signal using a power amplifier. The method includes providing the amplified RF signal to antennas. The antennas are caused to, upon receiving the amplified RF signal, radiate RF energy within a transmission field. The method includes determining predicted specific absorption rate (SAR) values of the transmission field and determining, based on the predicted SAR values, a keep out zone within the transmission field. The keep out zone is an area at which the predicted SAR values are greater than or equal to a predetermined SAR threshold of the transmission field. The method includes receiving, from sensors, an indication that an object is within the keep out zone. The method includes in response to receiving the indication, causing the antennas to cease radiating the RF energy.

Abstract: A wireless power transmitting system includes a power amplifier comprising a plurality of measurement points and a power amplifier controller integrated circuit (IC). In some embodiments, the power amplifier controller IC performs synchronization of the various components of the power amplifier, conducts impedance and temperature measurements at the measurements points, determines if a foreign object is within the transmission range of the wireless power transmitter, and decides if a shutdown of the power amplifier is needed. In some embodiments, the power amplifier controller IC determines through a transmitter controller IC, the presence of a foreign object within the transmission range and adjusts the power transmission to one or more receivers.

Abstract: Methods and devices for wireless power transmission are described. An example wireless-power-transmitting device includes a programmable-splitter component configured to be switchable between a linear polarization setting and a circular polarization setting. The example device also includes a plurality of polarization-switching components coupled to a plurality of outputs of the programmable-splitter component, and a plurality of amplifiers coupled to respective outputs of the plurality of polarization-switching components. The example device further includes a plurality of antennas coupled to respective outputs of the plurality of amplifiers.

Abstract: A wireless-power harvester integrated in a small device, comprising a stamped metal harvesting antenna. The stamped metal antenna is formed into a meandering shape. A first end of the meandering shape is a free end positioned within free space of a housing of a small device, and a second end of the meandering shape is coupled to a PCB that includes electrical components for operating and powering the small device. The PCB is configured to operate as a ground plane for the stamped metal antenna. An intermediate portion, disposed between the first end and the second end of the meandering shape, is coupled to power-conversion circuitry that is separate from the PCB. The power-conversion circuitry is configured to convert the one or more RF power waves harvested by the stamped metal harvesting antenna into usable energy for charging a battery of the small device or for powering the small device.

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 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 harvester integrated in a small device, comprising a stamped metal harvesting antenna. The stamped metal antenna is formed into a meandering shape. A first end of the meandering shape is a free end positioned within free space of a housing of a small device, and a second end of the meandering shape is coupled to a PCB that includes electrical components for operating and powering the small device. The PCB is configured to operate as a ground plane for the stamped metal antenna. An intermediate portion, disposed between the first end and the second end of the meandering shape, is coupled to power-conversion circuitry that is separate from the PCB. The power-conversion circuitry is configured to convert the one or more RF power waves harvested by the stamped metal harvesting antenna into usable energy for charging a battery of the small device or for powering the small device.

Abstract: A wireless power transmitting system includes a power amplifier comprising a plurality of measurement points and a power amplifier controller integrated circuit (IC). In some embodiments, the power amplifier controller IC performs synchronization of the various components of the power amplifier, conducts impedance and temperature measurements at the measurements points, determines if a foreign object is within the transmission range of the wireless power transmitter, and decides if a shutdown of the power amplifier is needed. In some embodiments, the power amplifier controller IC determines through a transmitter controller IC, the presence of a foreign object within the transmission range and adjusts the power transmission to one or more receivers.

Abstract: An example method is performed at a near-field charging pad with a processor, a power-transferring element, a signature-signal-receiving circuit, and the processor of the near-field charging pad is in communication with a data source that includes predefined signature signals that each identify one of (i) a wireless power receiver, (ii) an object other than a wireless power receiver, and (iii) a combination of a wireless power receiver and an object other than a wireless power receiver. The method includes: after sending a plurality of test radio frequency (RF) power transmission signals, detecting, using the signature-signal-receiving circuit, respective amounts of reflected power; generating, based on variations in the respective amounts of reflected power, a signature signal; and determining whether (i) an authorized wireless power receiver is present on the near-field charging pad and/or (ii) an object other than a wireless power receiver is present on the near-field charging pad.

Abstract: Methods and devices for surveying for active and inactive power receivers within a wireless-power coverage area are described. A method includes causing performance of a survey looking for active power receivers within a wireless-power coverage area using communication radio(s). Information is received from an active power receiver and transmission of RF signals is caused to energize inactive power receivers using a power-transmission antenna. A first RF signal is transmitted using a first value for a transmission characteristic, and a second RF signal is transmitted using a second value for the transmission characteristic. Additional information is received from a first energized power receiver and further information from a second energized power receiver. Two or more frequency bands are identified for radio-frequency wireless-power transmissions by a wireless-power transmitting device within the wireless-power coverage area based on the information, the additional information, and the further information.

Abstract: Systems and methods for controlling and managing operation of one or more power amplifiers to optimize the performance of one or more antennas are disclosed. An example wireless-power transmission system includes a power amplifier, one or more antennas, and one or more integrated circuits. The one or more integrated circuits are configured to adjust power provided to the one or more antennas from a power amplifier and adjust a power distribution for the transmission field based, in part, on the adjusted power provided to the one or more antennas from the power amplifier such that the adjusted power provided is evenly distributed across the power distribution for the transmission field of the antenna. The even distribution of the adjusted power results in a reduced power loss at an edge of the power distribution for the transmission field of the antenna from 30% to 10%.

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 wireless-power harvester integrated in a small device, comprising a stamped metal harvesting antenna. The stamped metal antenna is formed into a meandering shape. A first end of the meandering shape is a free end positioned within free space of a housing of a small device, and a second end of the meandering shape is coupled to a PCB that includes electrical components for operating and powering the small device. The PCB is configured to operate as a ground plane for the stamped metal antenna. An intermediate portion, disposed between the first end and the second end of the meandering shape, is coupled to power-conversion circuitry that is separate from the PCB. The power-conversion circuitry is configured to convert the one or more RF power waves harvested by the stamped metal harvesting antenna into usable energy for charging a battery of the small device or for powering the small device.

Abstract: Systems and methods for controlling and managing operation of one or more power amplifiers to optimize the performance of one or more antennas are disclosed. An example wireless-power transmission system includes a power amplifier, one or more antennas, and one or more integrated circuits. The one or more integrated circuits are configured to adjust power provided to the one or more antennas from a power amplifier and adjust a power distribution for the transmission field based, in part, on the adjusted power provided to the one or more antennas from the power amplifier such that the adjusted power provided is evenly distributed across the power distribution for the transmission field of the antenna. The even distribution of the adjusted power results in a reduced power loss at an edge of the power distribution for the transmission field of the antenna from 30% to 10%.

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 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 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.