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 charging pad for transmitting wireless power waves for charging an electronic device is disclosed. The charging pad includes transmitting antenna elements that are configured to be selectively activated to transmit wireless power waves to the electronic device for wireless charging. The charging pad includes a charging surface including a guiding contour that aligns a position of the electronic device on the charging surface such that a transmitting antenna element is within a predetermined distance of the electronic device and has a predetermined coupling efficiency. The charging pad further includes a transmitter controller integrated circuit (IC).

Abstract: An example system includes a wireless-power transmitter configured to emit a first set of one or more radio frequency (RB signals and a security camera coupled to a wireless-power receiver. The wireless-power receiver is configured to receive the first set of one or more RF signals. The security camera includes at least one component for converting energy from the first set of one or more RF signals into usable power to power the security camera. The usable power is a primary source of power for the security camera. The example system can also include a processor in communication with the wireless-power transmitter configured to, in accordance with a determination that the security camera has moved relative to the wireless-power transmitter, adjust the wireless-power transmitter to emit a second set of one or more RF signals from the wireless-power transmitter to continue providing usable power to the security camera.

Abstract: A near-field charging system for wirelessly charging electronic devices using electromagnetic energy having a low frequency is provided. The near-field charging system comprises: (A) a transmitting antenna comprising: a first substrate; and a first antenna, coupled to the first substrate, that follows a first meandering pattern having a first length, wherein the transmitting antenna has a first port impedance, and (B) a receiving antenna comprising: a second substrate; and a second antenna, coupled to the second substrate, that follows a second meandering pattern having a second length, wherein: (i) the second length is less than the first length, and (ii) the receiving antenna has a second port impedance that is less than the first port impedance. The transmitting antenna is configured to transmit electromagnetic energy having a frequency at or below 60 MHz to the receiving antenna at an efficiency above 90%.

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 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: Systems and methods for wireless power transmission based on object identification are provided. A radio frequency wireless power transmitter is in communication with a video camera for capturing image data (e.g., a visual pattern) of at least a portion of a transmission field of the radio frequency wireless power transmitter. A processor of the radio frequency wireless power transmitter is configured to identify an object when the visual pattern matches a pre-stored visual pattern representing the object, and control transmission of one or more radio frequency power transmission waves to a receiving electronic device based on a location of the identified object, wherein the receiving electronic device uses the one or more radio frequency power transmission waves to power or to charge the receiving electronic device.

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: An example wireless-power receiver comprises one or more processors configured to perform operations, including receiving, via one or more antenna elements of an antenna array, a plurality of first electromagnetic (EM) signals. Each antenna element of the one or more antenna elements of the antenna array has a respective polarization. The one or more processors are further configured to perform operations including, in response to a change in an orientation of the wireless-power receiver, changing the respective polarization to a changed polarization for the one or more antenna elements of the antenna array, and receiving, via the one or more antenna elements of the antenna array, and while the one or more antenna elements have the changed polarization, a plurality of second EM signals.

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: An example method performed by a wireless-power-transmitting device including an antenna array is provided. The method includes, based on a location of the wireless-power-receiving device, selecting a first value for a first transmission characteristic that is used for transmission of electromagnetic waves by a first antenna group, and a second value, distinct from the first value, for the first transmission characteristic that is used for transmission of electromagnetic waves by a second antenna group. The method also includes transmitting to the location of the wireless-power-receiving device, by the first antenna group, first electromagnetic waves with the first value for the first transmission characteristic, and transmitting to a focal point that is further from the wireless-power-transmitting device than the location of the wireless-power-receiving device, by the second antenna group, second electromagnetic waves with the second value for the first transmission characteristic.

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 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 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: 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 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 near-field charging system includes a housing that includes a charging surface and at least one other surface, a radiating antenna, and a non-radiating element positioned above the radiating antenna within the housing such that the non-radiating element is closer to the charging surface than the radiating antenna. The radiating antenna produces a first electromagnetic-field distribution that is received by a receiver, the first electromagnetic-field provides usable power when the receiver is placed at any position on a first portion of the charging surface. The non-radiating element changes a distribution characteristic of the first electromagnetic-field distribution to produce a second electromagnetic-field distribution, the second electromagnetic-field distribution providing usable power to the receiver when the receiver is placed at any position across a second portion of the charging surface of the housing, and the second portion is at least 10% percent greater than the first portion.

Abstract: An exemplary embodiment of a wireless power receiver comprises a wireless-power-receiving antenna configured to receive radio frequency (RF) signals, and convert energy from the received RF signals into an alternating current. The power receiver also comprises a primary rectifier configured to: (i) receive a first portion of the alternating current, and (ii) rectify the first portion of the alternating current into primary direct current having a first power level, the primary direct current used to provide power or charge to an electronic device; and a secondary rectifier configured to: (i) receive a second portion of the alternating current, and (ii) rectify the second portion of the alternating current into a secondary direct current having a second power level. The second power level of the secondary direct current is less than the first power level of the primary direct current.