Apple Inc.

Rahul A Sabnani

Manjit S Walia

Soumya Mantha

Vaneet Pathak

Cheung-Wei Lam

Andro Radchenko

Martin Schauer

Yiling Xu

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.

Wireless charging device with sinusoidal pulse-width modulation

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.

Wireless power transmitting circuitry with multiple modes

Wireless power transmitting devices according to embodiments of the present technology may include a contact surface configured to support one or more wireless power receiving devices. The wireless power transmitting devices may include a plurality of coils. The wireless power transmitting devices may also include a shield positioned between the plurality of coils and the contact surface. The shield may include one or more shield members, each shield member axially aligned with a separate coil of the plurality of coils, and may include a multilayer structure exhibiting various conductivities.

Electric shielding structures

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Colma, CA, United States of America

Rahul A Sabnani