Wireless power transfer through embedded geometric configurations

• US 9,799,443 B2
• Filed: 06/12/2013
• Issued: 10/24/2017
• Est. Priority Date: 06/12/2012
• Status: Active Grant

• Current Assignee: The Florida International University Board of Trustees (State University System of Florida), Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: The Florida International University Board of Trustees (State University System of Florida), Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Georgakopoulos, Stavros, Tentzeris, Manos
• Primary Examiner(s): Jackson, Stephen W
• Assistant Examiner(s): Sun, Pinping
• Application Number:
  US13/916,121
• Publication Number:
  US 20130328408A1
• Time in Patent Office: 1,595 Days
• CPC Class Codes: H01F 27/006 with special arrangement or spacing of turns of the winding(s), e.g. to produce desired self-resonance
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10

Abstract

A wireless power transmission system includes a planar source conductor configured to generate a first periodically fluctuating electromagnetic near field in response to an alternating current received from the power source. A planar resonant source element is coplanar with the planar source conductor and has a first resonant frequency. The planar resonant source element has a Q factor that is at a maximum at the first resonant frequency. A planar resonant load element resonates at the first resonant frequency. A planar load conductor is electromagnetically coupled to and coplanar with the planar resonant load element and generates a current in response to the second periodically fluctuating electromagnetic near field from the planar resonant load element.

Claims

1. A device for transmitting power wirelessly, comprising:

(a) a source unit, including;

(i) an alternating current power source;

(ii) a non-spiral source conductor element electrically coupled to the alternating current power source; and

(iii) a resonant source element, that is coplanar with the source conductor element and that surrounds the source conductor element and that is physically decoupled from the source conductive element, the conductive resonant element having a resonant frequency and having a maximum Q factor at the resonant frequency, the resonant source element configured to resonate in response to the alternating current being applied to the source conductor element, the resonant source element comprising a first source conductive spiral, the first source conductive spiral having a helix radius and a cross sectional wire radius in which a ratio of the helix radius to the cross sectional wire radius is substantially 9.52 so as to achieve the maximum Q factor at the resonant frequency; and

(b) a load unit, including;

(i) a resonant load element that is spaced apart from and that is physically decoupled from the resonant source element, the resonant load element resonant at the resonant frequency and having a maximum Q factor at the resonant frequency, the resonant load element configured to resonate in response to resonance in the resonant source element, the resonant load element comprising a first load conductive spiral, the first load conductive spiral having a helix radius and a cross sectional wire radius in which a ratio of the helix radius to the cross sectional wire radius is substantially 9.52 so as to achieve the maximum Q factor at the resonant frequency;

(ii) a non-spiral load conductor element, that is coplanar with the resonant load element and that is disposed within the resonant load element and that is physically decoupled from the resonant load element; and

(iii) a load that is electrically coupled to the load conductor element, wherein the load conductor element is configured to apply electrical power to the load in response to resonance in the resonant load element.

2. The device of claim 1, wherein the resonant source element comprises a second source conductive spiral that is bifilar with the first source conductive spiral so that the resonant source element comprises two coplanar source conductive bifilar spirals.

3. The device of claim 2, further comprising a planar substrate and wherein the bifilar spirals include a conductive material that has been printed on the planar substrate.

4. The device of claim 1, wherein the resonant load element comprises a second load conductive spiral that is bifilar with the first load conductive spiral so that the resonant load element comprises two coplanar load conductive bifilar spirals.

5. A method of transmitting power from a source to a load, comprising:

(a) generating an alternating current at the source and causing the alternating current to flow through a source conductor element that is non-spiral;

(b) inductively coupling a periodic electromagnetic field resulting from the alternating current flowing through the source conductor element to a first resonant source element that is coplanar with the source conductor element and that surrounds the source conductor element, and wherein the first resonant source element comprises a first source conductive spiral, wherein the resonant source element has a resonant frequency at a frequency at which the resonant source element has a maximum Q factor, the first source conductive spiral having a helix radius and a cross sectional wire radius in which a ratio of the helix radius to the cross sectional wire radius is substantially 9.52 so as to achieve the maximum Q factor at the resonant frequency;

(c) inductively coupling the resonant source element to a first resonant load element, wherein the first resonant load element comprises a first source conductive spiral wherein the resonant load element has a resonant frequency that is the same as the resonant frequency of the resonant source element, which is a frequency at which the resonant load element has a maximum Q factor, the first load conductive spiral having a helix radius and a cross sectional wire radius in which a ratio of the helix radius to the cross sectional wire radius is substantially 9.52 so as to achieve the maximum Q factor at the resonant frequency;

(d) inductively coupling a load conductor element to the resonant load element that is non-spiral, wherein the load conductor element is coplanar with the first conductive spiral resonant load element, thereby inducing a current in the load conductor element; and

(e) applying the current induced in the load conductor element to the load.

6. The method of claim 5, wherein the resonant source element comprises a second source conductive spiral that is bifilar with the first source conductive spiral so that the resonant source element comprises two coplanar source conductive bifilar spirals.

7. The method of claim 6, wherein the resonant load element comprises a second load conductive spiral that is bifilar with the first load conductive spiral so that the resonant load element comprises two coplanar load conductive bifilar spirals.