WIRELESS POWER TRANSFER SYSTEMS, METHODS AND TRANSMITTERS THEREFOR

• US 20190140480A1
• Filed: 11/06/2017
• Published: 05/09/2019
• Est. Priority Date: 11/06/2017
• Status: Active Grant

• Current Assignee: Solace Power Inc.
• Original Assignee: Solace Power Inc.
• Inventors: ROUSE, Chris
• Granted Patent: US 10,447,089 B2
• Time in Patent Office: Days
• CPC Class Codes: H01P 3/16 Dielectric waveguides, i.e. without a longitudinal conductor
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/23 characterised by the type of transmitting antennas, e.g. directional array antennas or Yagi antennas

Abstract

A transmitter comprises a power source; a transmit resonator electrically connected to the power source via an electrically small transmission line; and a metamaterial transmission line (MMTL) electrically connected between the power source and the electrically small transmission line. The transmit resonator comprises at least two electrodes; and at least one inductive coil electrically connected to the electrodes. The transmit resonator is configured to generate an electric field when excited by the power source. The electrically small transmission line is shorter in length than a wavelength of excitation of a power signal generated by the power source. The MMTL is configured to counteract an effect of the electrically small transmission line. The MMTL has a negative phase velocity (NPV).

Claims

1. A transmitter comprising:

a transmit resonator electrically connected to a power source of the transmitter via an electrically small transmission line, the transmit resonator comprising;

at least two electrodes; and

at least one inductive coil electrically connected to the electrodes, wherein the transmit resonator is configured to generate an electric field when excited by the power source, wherein the electrically small transmission line is shorter in length than a wavelength of excitation of a power signal generated by the power source; and

a metamaterial transmission line (MMTL) electrically connected between the power source and the electrically small transmission line, the MMTL configured to counteract an effect of the electrically small transmission line, wherein the MMTL has a negative phase velocity (NPV).

2. The transmitter of claim 1, wherein the electrically small transmission line has a phase constant β

and a physical length Δ

z, and wherein

tan(β

Δ

z)≈

β

Δ

z.

3. The transmitter of claim 1, wherein the electrically small transmission line has a phase constant β

and a physical length Δ

z, and wherein β

Δ

z<

0.2 radians.

4. The transmitter of claim 1, wherein the electrically small transmission line has a physical length Δ

z, wherein the power signal has a wavelength λ

, and wherein Δ

z<

λ

/30.

5. The transmitter of claim 1, wherein the MMTL is configured to counteract the impedance transformation effect of the electrically small transmission line on an input impedance of the transmit resonator.

6. The transmitter of claim 1, wherein the MMTL comprises a unit cell.

7. The transmitter of claim 6, wherein the unit cell comprises a symmetrical T-network.

8. The transmitter of claim 7, wherein the symmetrical T-network comprises two series capacitors and a shunt inductor.

9. The transmitter of claim 8, wherein the capacitance of the capacitors is given by 2C₀ and the inductance of the inductor is given by L₀, wherein:

10. The transmitter of claim 6, wherein the unit cell comprises a symmetrical π

-network.

11. The transmitter of claim 1, wherein the MMTL comprises n unit cells, where n is a positive integer.

12. The transmitter of claim 1, further comprising the power source.

16. The system of claim 1, wherein the transmitter further comprises the power source.

13. A system comprising:

a transmitter comprising;

a transmit resonator electrically connected to a power source of the transmitter via an electrically small transmission line, the transmit resonator comprising;

at least two electrodes; and

at least one inductive coil electrically connected to the electrodes, wherein the transmit resonator is configured to generate an electric field when excited by the power source, wherein the electrically small transmission line is shorter in length than a wavelength of excitation of a power signal generated by the power source; and

a metamaterial transmission line (MMTL) electrically connected between the power source and the electrically small transmission line, the MMTL configured to counteract an effect of the electrically small transmission line, wherein the MMTL has a negative phase velocity (NPV); and

a receiver configured to extract power from the generated electric field via resonant electric field coupling.

14. The system of claim 13, wherein the receiver further comprises:

a load; and

a receive resonator electrically connected to the load.

15. The system of claim 14, wherein the receive resonator comprises:

at least two electrodes; and

at least one inductive coil electrically connected to the electrodes of the receiver, wherein the receive resonator is configured to receive power transmit resonator via resonant electric field coupling.