Wireless power transfer using direct field penetration through a metal object
An apparatus for wireless power reception in an electronic device may include a casing configured to house electronic components of the electronic device. The casing may include a non-conductive support substrate and a metal layer disposed on the support substrate. The apparatus may include a power receiving element configured to magnetically couple to an externally generated magnetic field to produce power for one or more of the electronic components of the electronic device.
1. An apparatus for wireless power reception in an electronic device, the apparatus comprising:
a metal casing portion configured to house electronic components of the electronic device and to produce eddy currents through the metal casing portion in response to an exterior side of the metal casing portion being exposed to a first magnetic field; and
a power receiving element positioned on an interior side of the metal casing portion, the power receiving element configured to magnetically couple to a second magnetic field generated by the eddy currents in the metal casing portion to produce power for one or more of the electronic components of the electronic device;
wherein the power receiving element is arranged relative to an area of the metal casing portion that defines a continuous, unbroken, uninterrupted surface.
2. The apparatus of claim 1 , further comprising a ferrite material disposed between the power receiving element and the metal casing portion.
3. The apparatus of claim 1 , further comprising a ferrite material having first and second portions that sandwich the power receiving element between the first and second portions.
4. The apparatus of claim 1 , wherein the metal casing portion comprises at least one of copper, aluminum, magnesium, carbon steel, titanium, or stainless steel, or a combination thereof.
5. The apparatus of claim 1 , wherein the metal casing portion has a thickness of 0.01 mm or less.
6. The apparatus of claim 1 , wherein the metal casing portion comprises a non-conductive support substrate and a metal layer disposed on the support substrate.
7. The apparatus of claim 6 , wherein the metal layer has a thickness of 0.01 mm or less.
8. The apparatus f claim 6 , wherein a frequency of the externally generated first magnetic field is 300 KHz or less.
9. The apparatus of claim 6 , wherein the support substrate comprises a carbon-fiber compound, carbon nanotube materials, ceramics based materials, or fiberglass, or a combination thereof.
10. The apparatus of claim 6 , wherein at least a part of the interior side of the metal casing portion is flat and the power receiving element comprises a planar coil lying in a plane parallel to the at least a part of the interior side of the metal casing portion.
11. A method for wireless power reception in an electronic device comprising:
inducing eddy currents through at least a given area of a metal back cover defined by a continuous, unbroken, uninterrupted portion of material that comprises the metal back cover in response to exposing an exterior side of the metal back cover to an externally generated first magnetic field;
generating a second magnetic field that emanates from an interior side of the metal back cover in response to the induced eddy currents;
coupling the second magnetic field to a power receiving element that is disposed within the given area of the metal back cover; and
providing generated power from the power receiving element to one or more electronic components of the electronic device.
12. The method of claim 11 , further comprising coupling the second magnetic field to the power receiving element using a ferrite material.