INCREASING THE Q FACTOR OF A RESONATOR

• US 20090051224A1
• Filed: 08/11/2008
• Published: 02/26/2009
• Est. Priority Date: 03/02/2007
• Status: Active Grant

• Current Assignee: Nigel Power LLC (Qualcomm, Inc.)
• Original Assignee: Nigel Power LLC (Qualcomm, Inc.)
• Inventors: Widmer, Hanspeter, Sieber, Lukas, Cook, Nigel P.
• Granted Patent: US 8,482,157 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/23 characterised by the type of transmitting antennas, e.g. directional array antennas or Yagi antennas
• CPC Class Codes: H02J 50/27 characterised by the type of receiving antennas, e.g. rectennas

Abstract

A wireless powering and charging system is described. The antennas can be high q loop antennas. The antennas can use coupling between a first part and a second part.

Claims

1. A transmitter system for transmitting wireless electrical power, comprising:

a source which creates an output electrical signal having a specified frequency;

a coupling part, directly connected to said source, said coupling part formed of a first loop of wire which is impedance matched to said source; and

an antenna part, spaced from said coupling loop such that it is not directly connected to said coupling part, but magnetically coupled to a magnetic field created by said coupling part, said antenna part having no wired electrical connection thereto and receiving power wirelessly from said coupling loop, and said antenna part creating a magnetic field based on said power that is wirelessly received, said antenna part formed of an wire coil having an inductance L, and a capacitor having a capacitance C, and said antenna part having an LC value which is substantially resonant with said specified frequency.

2. A system as in claim 1, wherein said antenna part has a quality factor greater than 500.

3. A system as in claim 1, wherein said antenna part is formed on a substrate that supports said antenna part, and said substrate has a quality factor which is greater than 500.**

4. A system as in claim 2, wherein said antenna part is formed with an integral capacitor made from a vacuum capacitor.

5. A system as in claim 2, wherein said antenna part has a an inductive coil loop, and a capacitor connected across a portion of said inductive coil loop.

6. A system as in claim 5, further comprising a cube shaped housing in which said capacitor is housed.

7. A system as in claim 5, wherein said antenna part has a single turn in the coil loop.

8. A system as in claim 5, wherein said antenna has two turns in the coil loop.

9. A system as in claim 1, further comprising a receiver for the electrical power, where the receiver includes an antenna that is tuned to said specified frequency.

10. A system as in claim 9, wherein the receiver has a quality factor value that is lower than a quality factor value of the transmitter.

11. A system as in claim 9, wherein the receiver has a quality factor that is equal to or less than ¼

of the quality factor of the transmitter.

12. A system as in claim 9, wherein the receiver antenna has a size that is smaller than a size of the transmitter antenna.

13. A system as in claim 9, wherein the transmitter antenna and receiver antenna coupled to one another in order to form an energy link that is operative like a loosely coupled transformer.

14. A system as in claim 1, wherein said quality factor is a ratio of a resonant frequency of the antenna to a half power bandwidth of the antenna.

15. A system as in claim 1, wherein said capacitor has a Q of at least 1000.

16. A system as in claim 1, further comprising an attachment part across distal edges of material defining a loop, said attachment part holding a vacuum capacitor.

17. A receiver system for receiving wireless electrical power, comprising:

an antenna part, having no wired electrical connection thereto, configured for receiving a magnetic field, said antenna part formed of an inductive part with an inductance L and a capacitive part with a capacitance C, collectively defining an LC value which are substantially resonant with a specified frequency; and

a coupling loop, spaced from said antenna part, such that said coupling loop is not directly connected to said antenna part, but is magnetically connected to said antenna part, said coupling part receiving a signal having said specified frequency from said antenna part, and creating a power output based thereon.

18. A system as in claim 17, further comprising an electrical circuit that receives said power output and creates output power based thereon.

19. A system as in claim 18, wherein said antenna part has a quality factor greater than 500.

20. A system as in claim 18, wherein said antenna part is formed on a substrate that supports said antenna part, and said substrate has a quality factor which is greater than 500.

21. A system as in claim 19, wherein said antenna part is formed with an integral capacitor made from a vacuum capacitor.

22. A system as in claim 19, wherein said antenna part has an inductive coil loop, and a capacitor connected across a portion of said inductive coil loop.

23. A system as in claim 22, further comprising a cube shaped housing in which said capacitor is housed.

24. A system as in claim 22, wherein said antenna part has a single turn in the coil loop.

25. A system as in claim 22, wherein said antenna has two turns in the coil loop.

26. A system as in claim 19, further comprising a transmitter for the electrical power, where the transmitter includes an antenna that is tuned to said specified frequency.

27. A system as in claim 26, wherein the transmitter has a quality factor value that is lower than a quality factor value of the transmitter.

28. A system as in claim 26, wherein the transmitter has a quality factor that is equal to or less than ¼

of the quality factor of the transmitter.

29. A system as in claim 26, wherein the transmitter antenna has a size that is smaller than a size of the transmitter antenna.

30. A system as in claim 26, wherein the transmitter antenna and receiver antenna coupled to one another in order to form an energy link that is operative like a loosely coupled transformer.

31. A system as in claim 26, wherein said quality factor is a ratio of a resonant frequency of the antenna to a half power bandwidth of the antenna.

32. A system as in claim 26, wherein said capacitor has a Q of at least 1000.

33. A system as in claim 26, wherein said capacitor is a vacuum capacitor.

34. A method, comprising:

creating a magnetic field at a specified frequency based on applied power using a first loop antenna which includes no seperate capacitor attached thereto; and

coupling a portion of the wireless power between said first loop antenna and a second loop antenna that are associated with one another and are not electrically connected to one another, where said second loop antenna has a capacitor element that is separate from said loop, and where said second loop antenna has a resonant value at said first specified frequency.

35. A method as in claim 34, wherein said first and second loop antennas are both transmit antennas.

36. A method as in claim 34, wherein said coupling comprises coupling using a loosely-coupled transformer coupling.

37. A method, comprising:

receiving a magnetic field at a specified frequency based on applied power using a first loop antenna that has a capacitor element that is separate from said loop, and where said second loop antenna has a resonant value at said specified frequency; and

coupling a portion of the wirelessly-received magnetic field between said first loop antenna and a second loop antenna that are associated with one another and are not electrically connected to one another, and where said second loop antenna has no separate capacitor attached thereto; and

rectifying an output from said second loop antenna to create a DC output.

38. A method as in claim 37, wherein said first and second loop antennas are both receive antennas.

39. A method as in claim 37, wherein said coupling comprises coupling using a loosely-coupled transformer coupling.