Abstract: An electronic device may include wireless circuitry with a processor, a transceiver circuit, a front-end module, and an antenna array having multiple antennas. The front-end module may include radio-frequency splitter-combiner circuitry that splits radio-frequency signals from a single port into multiple radio-frequency signals at multiple split ports and/or combines radio-frequency signals from the multiple ports into radio-frequency signals at the single combined port. The radio-frequency splitter-combiner may include adjustable components such as switches, adjustable inductors, and/or adjustable capacitors that place the radio-frequency splitter-combiner in different configurations based on whether or not there are inactive split ports coupled to inactive antennas. This enables improved impedance matching for active split ports even while one or more split ports remain inactive, thereby reducing power loss in this mode of operation.

Abstract: An electronic device may include wireless circuitry with a processor, a transceiver circuit, a front-end module, and an antenna array having multiple antennas. The front-end module may include radio-frequency splitter-combiner circuitry that splits radio-frequency signals from a single port into multiple radio-frequency signals at multiple split ports and/or combines radio-frequency signals from the multiple ports into radio-frequency signals at the single combined port. The radio-frequency splitter-combiner may include adjustable components such as switches, adjustable inductors, and/or adjustable capacitors that place the radio-frequency splitter-combiner in different configurations based on whether or not there are inactive split ports coupled to inactive antennas. This enables improved impedance matching for active split ports even while one or more split ports remain inactive, thereby reducing power loss in this mode of operation.

Abstract: A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may include an inverter configured to drive a resonant circuit and may further include a sinusoidal pulse-width modulation (PWM) signal generator configured to generate a corresponding sinusoidal PWM control signal. The inverter may have an input that receives the sinusoidal PWM control signal. The sinusoidal PWM control signal may exhibit a plurality of different pulse widths summing to the target duty cycle of the sinusoidal PWM control signal. Operated in this way, the wireless power transmitting device exhibits reduced harmonic distortions, which mitigates undesired radiated spurious emissions.

Abstract: A wireless power transmitting device includes a plurality of coils and respective wireless power transmitting circuitry coupled to each coil. The wireless power transmitting circuitry coupled to each coil may include an inverter and adjustable circuitry that is configured to mitigated radiated emissions in nominally passive coils in the power transmitting device. The wireless power transmitting circuitry coupled to each coil in the wireless power transmitting device may include adjustable circuitry coupled to an inverter output terminal in parallel or in series with the coil. The adjustable circuitry may have a variable capacitance that is controlled based on whether the coil is in an active or passive mode. The capacitance of the adjustable circuitry may be varied in a repeating cycle when the coil is in a passive mode. The adjustable circuitry may include one or more capacitors coupled between the inverter output terminal and ground.

Abstract: A wireless power transmitting device includes a plurality of coils and respective wireless power transmitting circuitry coupled to each coil. The wireless power transmitting circuitry coupled to each coil may include an inverter and adjustable circuitry that is configured to mitigated radiated emissions in nominally passive coils in the power transmitting device. The wireless power transmitting circuitry coupled to each coil in the wireless power transmitting device may include adjustable circuitry coupled to an inverter output terminal in parallel or in series with the coil. The adjustable circuitry may have a variable capacitance that is controlled based on whether the coil is in an active or passive mode. The capacitance of the adjustable circuitry may be varied in a repeating cycle when the coil is in a passive mode. The adjustable circuitry may include one or more capacitors coupled between the inverter output terminal and ground.

Abstract: A wireless power system has a wireless power transmitting device and a wireless power receiving device. The wireless power transmitting device may include an inverter configured to drive a resonant circuit and may further include a sinusoidal pulse-width modulation (PWM) signal generator configured to generate a corresponding sinusoidal PWM control signal. The inverter may have an input that receives the sinusoidal PWM control signal. The sinusoidal PWM control signal may exhibit a plurality of different pulse widths summing to the target duty cycle of the sinusoidal PWM control signal. Operated in this way, the wireless power transmitting device exhibits reduced harmonic distortions, which mitigates undesired radiated spurious emissions.