Circuits and systems for wireless power transmission

Patent metadata

Field	Value
Publication number	US-10680466-B2
Application number	US-201815923631-A
Country	US
Kind code	B2
Filing date	Mar 16, 2018
Priority date	Mar 17, 2017
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

Circuits and systems for wireless power transmission include a driver circuit having first and second power terminals, a tapped coil, a first resonant tank, and a second resonant tank. The tapped coil includes a first, second, and third coil terminals, a first coil connected between the first and second coil terminals, and a second coil connected between the second and third coil terminals. The first resonant tank is coupled between the first and second power terminals. The second resonant tank is coupled between the first and second power terminals. The driver circuit is configured to provide and/or receive modulated power across the first and second power terminals and operate the device by switching between a first mode wherein the first resonant tank uses the first coil and a second mode wherein the second resonant tank uses the first coil and the second coil.

First claim

What is claimed is:

1. A wireless power transceiver, the transceiver comprising:
a driver circuit having a first power terminal and a second power terminal;
a tapped coil comprising:
a first coil terminal, a second coil terminal, and a third coil terminal, the first coil terminal being coupled to the first power terminal;
a first coil connected between the first coil terminal and the second coil terminal; and
a second coil connected between the second coil terminal and the third coil terminal;

a first resonant tank coupled between the first power terminal and the second power terminal; and
a second resonant tank coupled between the first power terminal and the second power terminal;
wherein the driver circuit is configured to:
provide and/or receive modulated power across the first and second power terminals; and
operate the transceiver by switching between two modes:
a first mode wherein the first resonant tank uses the first coil; and
a second mode wherein the second resonant tank uses the first coil and the second coil.

2. The transceiver of claim 1 , wherein:
the first resonant tank comprises a first capacitor coupled between the second coil terminal and the second power terminal;
the second resonant tank comprises a second capacitor coupled between the third coil terminal and the second power terminal; and
the first coil terminal is coupled to the first power terminal.

3. The transceiver of claim 2 , wherein:
the first capacitor is coupled between the second coil terminal and the second power terminal using a first switch; and
the second capacitor is coupled between the third coil terminal and the second power terminal using a second switch.

4. The transceiver of claim 3 , wherein the driver circuit is further configured to:
operate the transceiver in the first mode by turning the first switch on and turning the second switch off; and
operate the transceiver in the second mode by turning the first switch off and turning the second switch on.

5. The transceiver of claim 3 , wherein the first and second switches are n-channel MOSFETs.

6. The transceiver of claim 1 , further comprising a startup circuit configured to apply power to the first coil before operating the transceiver in the first or second modes.

7. The transceiver of claim 1 , wherein:
the driver circuit further comprises a full bridge driver with outputs connected to the first and second power terminals; and
the driver circuit operates the full bridge driver to provide the modulated power to and/or receive the modulated power from the first resonant tank or the second resonant tank.

8. The transceiver of claim 1 , wherein the first coil is nested within the second coil.

9. The transceiver of claim 1 , wherein when the transceiver is operated in the first mode, the first coil is a receiver or transmitter operating in a first frequency range.

10. The transceiver of claim 9 , wherein when the transceiver is operated in the second mode, the first and second coils are a receiver or transmitter operating in a second frequency range.

11. A wireless power transceiver, the transceiver comprising:
a driver circuit having a first power terminal and a second power terminal;
a tapped coil comprising:
a first coil terminal, a second coil terminal, and a third coil terminal, the first coil terminal being coupled to the first power terminal;
a first coil connected between the first coil terminal and the second coil terminal; and
a second coil connected between the second coil terminal and the third coil terminal;

a first capacitor coupled between the second coil terminal and the second power terminal;
a second capacitor coupled between the third coil terminal and the second power terminal;
a first switch coupling the first capacitor between the second coil terminal and the second power terminal; and
a second switch coupling the second capacitor between the third coil terminal and the second power terminal;
wherein the driver circuit is configured to:
provide and/or receive modulated power across the first and second power terminals; and
control the first and second switches to operate the first coil and the first capacitor as a first resonant tank or the first and second coils and the second capacitor as a second resonant tank.

12. The transceiver of claim 11 , wherein the driver circuit is further configured to operate the first coil and the first capacitor as a first resonant tank by turning the first switch on and turning the second switch off.

13. The transceiver of claim 12 , wherein the first resonant tank forms a receiver or transmitter operating in a first frequency range.

14. The transceiver of claim 11 , wherein the driver circuit is further configured to operate the first coil, the second coil, and the second capacitor as a second resonant tank by turning the first switch off and turning the second switch on.

15. The transceiver of claim 14 , wherein the second resonant tank form a receiver or transmitter operating in a second frequency range.

16. The transceiver of claim 11 , wherein the first and second switches are n-channel MOSFETs.

17. The transceiver of claim 11 , further comprising a startup circuit configured to apply power to the first coil to bias the first and second switches before operating the first and second switches.

18. The transceiver of claim 11 , wherein:
the driver circuit further comprises a full bridge driver with terminals connected to the first and second power terminals; and
the driver circuit operates the full bridge driver to modulate power to and/or receive modulated power from the first and second power terminals.

Assignees

• Integrated Device Tech

Inventors

• Liu Rui
• Qi Tao

Classifications

• H01F38/14

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

• H02J7/025

  Electricity · mapped topic

• H02J50/12 Primary

  of the resonant type · CPC title

• H01F27/29

  Terminals; Tapping arrangements {for signal inductances} · CPC title