Apple Inc.
Electromagnetic shielding for wireless power transfer systems

Abstract:

Embodiments describe electromagnetic shielding for wireless charging systems. A wireless charging system includes a transmitter coil configured to generate a magnetic flux, a receiver coil positioned coaxial with the transmitter coil to receive the generated magnetic flux, where electrical interaction between the transmitter coil and the receiver coil generates electric fields, a transmitter shield positioned between the transmitter coil and the receiver coil to intercept some of the electric fields directed away from the transmitter coil and allow the magnetic flux to pass through the transmitter shield, and a receiver shield positioned between the transmitter shield and the receiver coil to intercept some of the electric fields directed away from the receiver coil and allow the magnetic flux to pass through the receiver shield.