Wireless power transfer using multiple near-field plates

Patent metadata

Field	Value
Publication number	US-9793720-B2
Application number	US-201514958579-A
Country	US
Kind code	B2
Filing date	Dec 3, 2015
Priority date	Apr 16, 2014
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

A near-field plate is a non-periodically patterned surface that can overcome the diffraction limit and confine electromagnetic fields to subwavelength dimensions. By controlling the interference of the electromagnetic fields radiated by the near-field plate with that of a source, the near-field plate can form a subwavelength near-field pattern in a forward direction, while suppressing fields in other directions, such as those reflected. The resulting unidirectional near-field plate may find utility in many applications such as high resolution imaging and probing, high density data storage, biomedical targeting devices, and wireless power transfer.

First claim

What is claimed:

1. A method for wireless transfer of power from a transmitting side to a receiving side, the method comprising:
generating a source field pattern energy from an excitation power source at a focal plane of the transmitting side;
generating a subwavelength field pattern of energy from a transmitting side near-field plate when the near-field plate is excited by the excitation source, the transmitter side near-field plate being at a distance, d, from the excitation source;
receiving energy at the receiving side in a desired field pattern received by a receiving side near-field plate positioned to excite a power receiver, where the desired field pattern is formed at a focal plane of the receiving side and from the subwavelength field pattern and the source field pattern, the focal plane of the receiving side being at a distance, L, from the excitation source, and wherein the receiving side near-field plate is positioned at the focal plane of the receiving side; and
converting the received energy into a received power, at a power conversion efficiency.

2. The method of claim 1 , further comprising:
increasing the amplitude of the desired field pattern by varying an amplification factor at the transmitting side.

3. The method of claim 1 , further comprising:
increasing the power conversion efficiency at the receiving side by varying a distance between the receiving side near-field plate the power receiver.

4. The method of claim 1 , wherein the excitation power source is a transmitting loop and wherein the power receiver is a receiving loop.

5. The method of claim 4 , wherein the transmitting side near-field plate has the same configuration as the receiving side near field plate.

6. The method of claim 4 , wherein the transmitting side near-field plate has a different configuration than the receiving side near field plate.

7. The method of claim 4 , wherein the transmitting side near-field plate is formed of a plurality of concentric loops.

8. The method of claim 4 , wherein the receiving side near-field plate is formed of a plurality of concentric loops.

9. The method of claim 4 , wherein the transmitting loop comprises a multi-turn coil; and the receiving loop comprises a multi-turn coil.

10. The method of claim 1 , further comprising:
supplying the received power to a device for wirelessly power the device or wirelessly charging the device, wherein the device includes one or more of a computer, a smartphone, a biometric sensor device, a chargeable battery, or a vehicle using a chargeable battery.

11. An apparatus for wireless power transfer from a transmitting side to a receiving side, the apparatus comprising:
an excitation power source generating a source field pattern energy at the transmitting side;
a transmitting side near-field plate generating a subwavelength field pattern energy when excited by the excitation source, wherein after traversing a near-field distance, L, the source field pattern energy and the subwavelength field pattern energy form a desired field pattern energy at a focal plane, wherein the desired field pattern energy has a unidirectional subwavelength field pattern when the amplitude of the subwavelength field pattern is increased; and
a power receiver and a receiving side near-field plate at the receiving side, the receiving side near-field plate being positioned at the focal plane and spaced a distance from the power receiver to couple a received energy from desired field pattern energy to the power receiver, wherein the power receiver is configured to convert the received energy into a received power for provision to a load.

12. The apparatus of claim 11 , wherein the excitation power source is a transmitting loop and wherein the power receiver is a receiving loop.

13. The apparatus of claim 12 , wherein the transmitting side near-field plate has the same configuration as the receiving side near field plate.

14. The apparatus of claim 12 , wherein the transmitting side near-field plate has a different configuration than the receiving side near field plate.

15. The apparatus of claim 12 , wherein the transmitting side near-field plate is formed of a plurality of concentric loops.

16. The apparatus of claim 12 , wherein the receiving side near-field plate is formed of a plurality of concentric loops.

17. The apparatus of claim 12 , wherein the transmitting loop comprises a Würth coil; and the receiving loop comprises a Würth coil.

18. The apparatus of claim 12 , further wherein the load is a device to receive the received power for wirelessly powering the device or wirelessly charging the device, wherein the device includes one or more of a computer, a smartphone, a biometric sensor device, a chargeable battery, or a vehicle using a chargeable battery.

Assignees

• Univ Michigan Regents

Inventors

• Grbic Anthony
• Young Steve

Classifications

• Y02T10/7072

  Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors · CPC title

• H01F38/14

  Inductive couplings {(for wireless supply or distribution of electric power using inductive coupling H02J50/10)} · CPC title

• H02J50/12

  of the resonant type · CPC title

• H01F2038/146

  in combination with capacitive coupling · CPC title

• Y02T90/14

  Plug-in electric vehicles · CPC title