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: A wireless-power transmitter including an antenna including a plurality of power-transfer points. The antenna is configured to operate in multiple modes. The multiple modes include a standby mode and a single receiver power-transfer mode. The standby mode provides a signal to the antenna at predetermined time intervals. The signal causes the antenna to transmit electromagnetic energy that is below a threshold amount, and produce an electric field that is substantially equally distributed at each of the power-transfer points. The single receiver power-transfer mode is activated upon a wireless power-receiver coupling with one of the plurality of power-transfer points such that (i) a portion of the electric field is greater at the one of the plurality of the power-transfer points than at any other of the power-transfer points, and (ii) electromagnetic energy is transferred from the antenna to the wireless power-receiver at the one of the plurality of the power-transfer points.

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: 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.