Wireless energy transfer for wearables
View Patent ↗The disclosure features resonators to wirelessly transfer energy to a wireless power device including a device resonator coil having a dimension D. The resonator can include a first plurality of conductor windings wound approximately in a first plane and having first and second conductor leads, and a second plurality of conductor windings wound in a second plane and having third and fourth conductor leads. The first and third conductor leads can be coupled to each other and the second and the fourth conductor leads can be coupled to at least one capacitor. The first plane and second plane can be spaced apart by separation S and substantially parallel. The separation S between the first plane and second plane can be approximately equal to or greater than the dimension D of the device resonator coil.
1. A resonator to wirelessly transfer energy to a wireless power device comprising a device resonator coil having a dimension D, the resonator comprising:
a first plurality of conductor windings wound approximately in a first plane and having first and second conductor leads; and
a second plurality of conductor windings wound in a second plane and having third and fourth conductor leads;
wherein the first and third conductor leads are coupled to each other and the second and the fourth conductor leads are coupled to at least one capacitor;
wherein the first plane and second plane are spaced apart by separation S and substantially parallel; and
wherein the separation S between the first plane and second plane is approximately equal to or greater than the dimension D of the device resonator coil.
2. The resonator of claim 1 wherein, when driven with an oscillating current, the resonator generates an oscillating electromagnetic field.
3. The resonator of claim 2 wherein the first plurality of conductor windings has a first dipole and the second plurality of conductor windings has a second dipole and wherein normal components of the first and second dipole moments cancel each other.
4. The resonator of claim 3 wherein the electromagnetic field has a radial dipole through the separation S.
5. The resonator of claim 1 wherein the first and second plurality of conductor windings comprises copper, copper-clad aluminum, or Litz wire.
6. The resonator of claim 1 wherein the first and second plurality of conductor windings each comprises at least three turns.
7. The resonator of claim 1 wherein a length of an outermost winding of a third plurality of windings of the device resonator coil defines the dimension D.
8. The resonator of claim 1 wherein a first piece of magnetic material is disposed on a bottom surface of the first conductor wound in the first plane.
9. The resonator of claim 1 wherein a second piece of magnetic material is disposed on a top surface of the second conductor wound in the second plane.
10. The resonator of claim 1 wherein the resonator is a repeater resonator and wherein the first and second plurality of conductor windings are wound in a same direction.
11. The resonator of claim 1 wherein the resonator is a source resonator and wherein the first and second plurality of conductor windings are wound in different directions.
12. The resonator of claim 1 wherein a first portion of the first plurality of conductor windings is positioned above the first plane.
13. The resonator of claim 1 wherein a second portion of the first plurality of conductor windings is positioned below the first plane.
14. The resonator of claim 1 wherein a third portion of the first plurality of conductor windings is positioned in the first plane.
15. The resonator of claim 1 wherein a first portion of the second plurality of conductor windings is positioned above the second plane.
16. The resonator of claim 1 wherein a second portion of the second plurality of conductor windings is positioned below the second plane.
17. The resonator of claim 1 wherein a third portion of the second plurality of conductor windings is positioned in the second plane.
18. The resonator of claim 1 wherein at least one of the first or second plurality of conductor windings forms a stacked ring.
19. The resonator of claim 1 wherein at least one of the first or second plurality of conductor windings forms a cylindrical shape.
20. A wireless power transfer system comprising:
a source resonator comprising:
a first plurality of conductor windings wound in a first plane and having first and second conductor leads;
a second plurality of conductor windings wound in a second plane and having third and fourth conductor leads; and
a device resonator comprising a third plurality of conductor windings wound in a third plane having a dimension D;
wherein the first and third conductor leads are coupled to each other and the second and the fourth conductor leads are coupled to at least one capacitor;
wherein the first plane and second plane are spaced apart by separation S and substantially parallel; and
wherein separation S between the first plane and second plane is approximately equal to or greater than the dimension D of the device resonator coil.
21. The system of claim 20 wherein the first and second plurality of conductor windings disposed along an inner surface of a housing, the housing comprising non-conductive material.
22. The system of claim 21 wherein the first and second plurality of conductor windings contact the inner surface of the housing.