Self-canceling magnetic structures for transferring power and communication signals

• US 10,348,367 B2
• Filed: 03/28/2018
• Issued: 07/09/2019
• Est. Priority Date: 03/14/2016
• Status: Active Grant

• Current Assignee: Quanten Technologies Limited
• Original Assignee: X2 Power Technologies Limited
• Inventors: Mao, Hengchun, Yang, Bo
• Primary Examiner(s): Sandiford, Devan A
• Application Number:
  US15/938,189
• Publication Number:
  US 20180219586A1
• Time in Patent Office: 468 Days
• CPC Class Codes: H01F 2027/2809 on stacked layers
• CPC Class Codes: H01F 2038/143 for signals
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 27/29 Terminals; Tapping arrangements for signal inductances
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A structure comprises a first power coil configured to be magnetically coupled to a second power coil and an auxiliary coil over the first power coil, wherein at least one of the first power coil and the auxiliary coil has an 8-shaped structure.

Claims

1. A structure comprising:

a first power coil configured to be magnetically coupled to a second power coil; and

an auxiliary coil over the first power coil, wherein at least one of the first power coil and the auxiliary coil has an 8-shaped structure, and wherein the auxiliary coil is a bias coil for supplying a bias voltage in a wireless power transfer system.

2. The structure of claim 1, wherein:

the auxiliary coil has the 8-shaped structure including a self-enclosed magnetic path.

3. The structure of claim 2, wherein:

the 8-shaped structure includes a first portion and a second portion, and wherein each portion comprises a straight line and an arc, and wherein a straight line of the first portion and a straight line of the second portion are placed adjacent to each other.

4. The structure of claim 1, wherein:

an outermost edge of the auxiliary coil is outside of the first power coil.

5. The structure of claim 1, wherein:

the auxiliary coil is surrounded by the first power coil.

6. The structure of claim 1, wherein:

the at least one of the first power coil and the auxiliary coil is formed in two different layers of a printed circuit board.

7. A device comprising:

a first coil over a second coil, wherein;

at least one of the first coil and the second coil is configured to be magnetically coupled to a third coil; and

at least one of the first coil and the second coil comprises a first portion having a first almost enclosed shape and a second portion having a second almost enclosed shape, and wherein the first portion and the second portion are arranged to enhance a magnetic field strength at a center portion of the device, and wherein the first portion comprises a first straight line and a first arc, and the second portion comprises a second straight line and a second arc, and wherein the first straight line and the second straight line are in parallel and immediately adjacent to each other.

8. The device of claim 7, wherein:

the first portion and the second portion form an 8-shaped structure.

9. The device of claim 8, wherein:

the first coil has the 8-shaped structure and the first coil is configured to transfer power; and

the second coil has a plurality of turns and the second coil is configured to transfer communication signals.

10. The device of claim 8, wherein:

the first coil has a plurality of turns and the first coil is configured to transfer power; and

the second coil has the 8-shaped structure and the second coil is configured to transfer communication signals.

11. The device of claim 7, wherein:

the first portion and the second portion are configured to flow a current from the first portion to the second portion, and wherein a first magnetic flux through the first portion and a second magnetic flux through the second portion are vertically opposite to each other.

12. A method comprising:

wirelessly transferring power from a plurality of first coils to a plurality of second coils, wherein at least one of the plurality of first coils comprises;

a first portion having a first almost enclosed shape; and

a second portion having a second almost enclosed shape, and wherein the first portion and the second portion are arranged such that a first magnetic flux through the first portion and a second magnetic flux through the second portion are opposite to each other with reference to a vertical axis perpendicular to the plurality of first coils and the plurality of second coils; and

transferring both power and communication signals by one of the plurality of first coils through a same in-band communication channel.

13. The method of claim 12, wherein:

the first portion is a first half circle; and

the second portion is a second half circle, and wherein the first half circle and the second half circle are immediately adjacent to each other.

14. The method of claim 13, wherein:

the plurality of first coils is placed at a transmitter; and

the plurality of second coils is placed at a receiver.

15. The method of claim 12, further comprising:

configuring a first coil of the plurality of first coils as a transmitter coil; and

configuring a second coil of the plurality of first coils as a receiver coil, wherein the first coil and the second coil are integrated in one coil structure.