Wireless energy transfer for mobile device applications

1. A wireless energy transfer system comprising:

a first layer of conductive material positioned proximate to a second layer;

the second layer of magnetic material positioned proximate to the first layer of conductive material and a third layer;

the third layer positioned proximate to the second layer and a fourth layer, the third layer includes a first resonator coil, wherein the first resonator coil is configured to transfer wireless energy to a second resonator coil when the second resonator coil is proximate to the first resonator coil; and

the fourth layer positioned proximate to the third layer, wherein the fourth layer includes a plurality of conductive material.

2. The system of claim 1 wherein at least one of a size, a shape, and a geometric position of the plurality of pieces of conductive material reduces inductance shifting in the second resonator coil when the first resonator coil is proximate to the second resonator coil.

3. The system of claim 2 wherein the shape is a rectangle.

4. The system of claim 2 wherein the shape is a square.

5. The system of claim 2 wherein at least a first portion of the plurality of pieces of the conductive material is a first shape, and wherein at least a second portion of the plurality of pieces of the conductive material is a second shape.

6. The system of claim 2 wherein at least a portion of the plurality of pieces of the conductive material are arranged in a checkered pattern relative to the first resonator coil.

7. The system of claim 1 wherein the first resonator coil includes copper trace.

8. The system of claim 1 wherein the magnetic material includes ferrite.

9. The system of claim 1 wherein the plurality of pieces of conductive material of the fourth layer includes copper.

10. The system of claim 1 wherein the first layer of conductive material includes copper.

11. The system of claim 1 wherein the first layer is configured to be coupled to a surface of a mobile battery unit.

12. The system of claim 1 wherein the magnetic material has a thickness less than 1 mm.

13. The system of claim 1 wherein the magnetic material has a thickness less than 0.5 mm.

14. The system of claim 1 wherein the first resonator coil is configured to transfer at least 5 W of energy to the second resonator coil.

15. The system of claim 1 wherein the first resonator coil is configured to transfer at least 10 W of energy to the second resonator coil.

16. A wireless energy transfer system comprising:

a first layer of conductive material positioned proximate to the second layer;

the second layer of magnetic material positioned proximate to the first layer of conductive material and a third layer;

the third layer positioned proximate to the second layer and a fourth layer, wherein the third layer includes a plurality of pieces of conductive material; and

the fourth layer positioned proximate to the third layer, the fourth layer includes a first resonator coil, wherein the first resonator coil is configured to transfer wireless energy to a second resonator coil when the second resonator coil is proximate to the first resonator coil.

17. The system of claim 16 wherein at least one of a size, a shape, and a geometric position of the plurality of pieces of conductive material reduces inductance shifting in the second resonator when the first resonator is proximate to the second resonator.

18. The system of claim 17 wherein at least a first portion of the plurality of pieces of the conductive material is a first shape, and wherein at least a second portion of the plurality of pieces of the conductive material is a second shape.

19. The system of claim 17 wherein at least a portion of the plurality of pieces of the conductive material are arranged in a checkered pattern relative to the first resonator.

20. The system of claim 16 wherein the plurality of pieces of conductive material of the fourth layer includes copper.