Abstract: An electronic device can include a metallic or non-metallic housing having a window therethrough, a wireless power transfer coil disposed inside the housing adjacent the window, and a non-metallic cover disposed within the window that protects the wireless power transfer coil, the non-metallic cover incorporating at least one ferromagnetic region that improves magnetic coupling of the wireless power transfer coil to a corresponding wireless power transfer coil of another device by providing a high magnetic permeability flux path. The non-metallic cover and the at least one ferromagnetic region have surface finishes selected to visually match or coordinate with the housing.

Abstract: A magnetic alignment assembly can be incorporated into an electronic device to facilitate alignment with another device. The magnetic alignment assembly can include a main magnet (e.g., a square or rectangular magnet) having a magnetic dipole in an axial direction and a ring magnet coaxial with the main magnet. The ring magnet can be smaller than the main magnet. The ring magnet can be positioned between the main magnet and an interface surface.

Abstract: In a wireless charging system, a transmitter coil of a wireless charger device and a receiver coil of a portable electronic device can operate at either of two different operating frequencies. The low frequency can be in a range from about 300 kHz to about 400 kHz, and the high frequency can be in a range from about 1 MHz to about 2 MHz. To provide efficient charging at both frequencies, the transmitter and receiver coils can be formed from a compound, or multi-stranded, wire.