Wireless Power Transmission Antenna with Thermally Conductive Magnetic Shield and Method Therefor

• US 20170063132A1
• Filed: 09/01/2015
• Published: 03/02/2017
• Est. Priority Date: 09/01/2015
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Sultenfuss, Andrew T., North, Travis C.
• Granted Patent: US 9,912,187 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/366 made of ferromagnetic material
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/23 characterised by the type of transmitting antennas, e.g. directional array antennas or Yagi antennas
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/43 Antennas
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: H05K 9/00 Screening of apparatus or components against electric or magnetic fields devices for absorbing radiation from an antenna H01Q17/00

Abstract

A carbon material and a magnetic material are incorporated at a magnetic shield included at a wireless power antenna. The magnetic shield shapes a magnetic flux field proximate to the magnetic shield. The carbon material conducts heat at the magnetic shield.

Claims

1. A method comprising:

incorporating a carbon material and a magnetic material at a magnetic shield included at a wireless power antenna, the magnetic shield to shape a magnetic flux field proximate to the magnetic shield, the carbon material to provide thermal conductivity at the magnetic shield.

2. The method of claim 1, wherein the carbon material provides orthotropic thermal conductivity and is arranged to conduct heat in a direction parallel to a primary plane of the magnetic shield.

3. The method of claim 1, wherein the carbon material is arranged to conduct heat in a direction perpendicular to the primary plane of the magnetic shield.

4. The method of claim 1, wherein the carbon material includes carbon nanotubes.

5. The method of claim 1, wherein the carbon material includes graphite.

6. The method of claim 1, wherein incorporating the carbon material at the magnetic shield comprises laminating a first sheet including the magnetic material and a second sheet including the carbon material, a wireless power inductor to attach to a major surface of the first sheet opposite the second sheet.

7. The method of claim 1, wherein incorporating the carbon material at the magnetic shield comprises distributing chopped carbon nanotubes and the magnetic material homogeneously in a binder.

8. The method of claim 1, wherein incorporating the carbon material at the magnetic shield comprises arranging a plurality of carbon nanotubes in a substantially parallel orientation within a binder, the binder further including a distribution of powdered iron or a powdered ferrite.

9. The method of claim 1, wherein incorporating the carbon material at the magnetic shield comprises mixing carbon nanotubes in a binder and applying the mixture to a first major surface of a sheet of material containing powdered iron or a powdered ferrite, a wireless power inductor to attach to a second major surface opposite the first major surface.

10. A wireless power antenna device comprising:

an inductor; and

a magnetic shield including a magnetic material and a carbon material, the magnetic material to shape a magnetic flux field at the inductor, the carbon material to provide thermal conductivity at the magnetic shield.

11. The device of claim 10, wherein the carbon material provides orthotropic thermal conductivity and is arranged to conduct heat in a direction parallel to a primary plane of the magnetic shield.

12. The device of claim 10, wherein the carbon material is arranged to conduct heat in a direction perpendicular to the primary plane of the magnetic shield.

13. The device of claim 10, wherein the carbon material includes carbon nanotubes.

14. The device of claim 10, wherein the carbon material includes graphite.

15. The device of claim 10, wherein the magnetic shield further comprises a lamination of a first sheet including the magnetic material and a second sheet including the carbon material, the first sheet adjacent to the inductor.

16. The device of claim 10, wherein the magnetic material is included in a first sheet and the carbon material, suspended in an adhesive carrier is applied to a primary surface of the first sheet opposite the major surface to which the inductor is attached.

17. The device of claim 10, further comprising a heat sink coupled to the magnetic shield.

18. The device of claim 10, wherein the inductor is a wireless power source antenna to transmit power to a target antenna, or a wireless power target antenna to receive power from a wireless power source antenna.

19. The device of claim 10, wherein the magnetic material includes powdered iron or a ferrite material.

20. A wireless charging system comprising:

a wireless charging controller; and

a wireless charging antenna assembly coupled to the wireless charging controller, the antenna assembly including;

an inductor; and

a magnetic shield including a magnetic material and a carbon material, the magnetic material to shape a magnetic flux field at the inductor, the carbon material to provide thermal conductivity at the magnetic shield.