Wireless power transfer structure
An electronic device can include a metallic housing defining an interior that contains one or more systems of the electronic device. The metallic housing can further define a pocket within the metallic housing separated from the interior. The pocket can have a window to an exterior of the metallic housing to facilitate wireless power transfer. An electronic device can include a non-metallic housing defining an interior that contains one or more systems of the electronic device and a wireless power transfer module that further includes a metallic structure defining a receptacle separated from the interior housing. The receptacle can have at least one open side to facilitate wireless power transfer. In either case, the wireless power transfer coil can be disposed at least partially or completely within the pocket or receptacle.
1. An electronic device comprising:
a metallic housing defining an interior that contains one or more systems of the electronic device, the metallic housing further defining a pocket inside the metallic housing separated from the interior, the pocket having a window to an exterior of the metallic housing to facilitate wireless power transfer; and
a wireless power transfer coil comprising a magnetic core and a winding disposed inside the metallic housing at least partially within the pocket.
2. The electronic device of claim 1 wherein the wireless power transfer coil is disposed completely within the pocket.
3. The electronic device of claim 1 wherein the magnetic core is a nickel-zinc ferrite.
4. The electronic device of claim 1 wherein:
the magnetic core has a C-shaped cross section;
ends of the C-shaped cross section are disposed within or adjacent the window; and
the winding is wrapped about a central portion of the C-shaped cross section.
5. The electronic device of claim 4 wherein the winding is a single layer winding.
6. The electronic device of claim 5 wherein the winding further comprises a plurality of wire strands per turn.
7. The electronic device of claim 5 wherein the winding further comprises one or more non-metallic spacers disposed between strands of the winding.
8. The electronic device of claim 1 further comprising a conductive shim disposed between the wireless power transfer coil and a metallic wall defining the pocket.
9. The electronic device of claim 8 , wherein the conductive shim is formed of copper tape affixed to the metallic wall defining the pocket.
10. The electronic device of claim 1 wherein the pocket serves as a shield to isolate the one or more systems of the electronic device from the wireless power transfer coil.
11. An electronic device comprising:
a non-metallic housing defining an interior that contains one or more systems of the electronic device; and
a wireless power transfer module that further comprises:
a metallic structure defining a receptacle disposed inside and separated from the interior of the non-metallic housing, the receptacle having at least one open side to facilitate wireless power transfer; and
a wireless power transfer coil comprising a magnetic core and a winding disposed at least partially within the receptacle.
12. The electronic device of claim 11 wherein the metallic structure defining the receptacle is affixed to the non-metallic housing.
13. The electronic device of claim 11 wherein the wireless power transfer coil is disposed completely within the receptacle.
14. The electronic device of claim 11 wherein the magnetic core is a nickel-zinc ferrite.
15. The electronic device of claim 11 wherein:
the magnetic core has a C-shaped cross section;
ends of the C-shaped cross section are disposed within or adjacent the open side; and
the winding is wrapped about a central portion of the C-shaped cross section.
16. The electronic device of claim 15 wherein the winding is a single layer winding.
17. The electronic device of claim 16 wherein the winding further comprises a plurality of wire strands per turn.
18. The electronic device of claim 16 wherein the winding further comprises one or more non-metallic spacers disposed between strands of the winding.
19. The electronic device of claim 11 further comprising a conductive shim disposed between the wireless power transfer coil and the metallic structure defining the receptacle.
20. The electronic device of claim 19 , wherein the conductive shim is formed of copper tape affixed to the metallic structure defining the receptacle.
21. The electronic device of claim 11 wherein the receptacle serves as a shield to isolate the one or more systems of the electronic device from the wireless power transfer coil.
22. A wireless power transfer module comprising:
a metallic structure defining a receptacle having at least one open side to facilitate wireless power transfer; and
a wireless power transfer coil comprising a magnetic core and a winding disposed at least partially within the receptacle;
wherein:
the magnetic core has a C-shaped cross section;
ends of the C-shaped cross section are disposed within or adjacent the open side; and
the winding is a single-layer winding wrapped about a central portion of the C-shaped cross section.
23. The wireless power transfer module of claim 22 wherein the winding further comprises a plurality of wire strands per turn.
24. The wireless power transfer module of claim 22 wherein the winding further comprises one or more non-metallic spacers disposed between strands of the winding.