Increasing the Q factor of a resonator

• US 8,482,157 B2
• Filed: 08/11/2008
• Issued: 07/09/2013
• Est. Priority Date: 03/02/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Cook, Nigel, Sieber, Lukas, Widmer, Hanspeter
• Primary Examiner(s): DeBeradinis, Robert L.
• Application Number:
  US12/189,433
• Publication Number:
  US 20090051224A1
• Time in Patent Office: 1,793 Days
• Field of Search: 307/104
• 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 electrical power via a wireless field, comprising:

a source configured to produce an output electrical signal having a first frequency;

a non-resonant coupling part, physically connected to said source, said coupling part including a first loop of wire; and

a resonant antenna part, spaced from said coupling part such that said antenna part is galvanically isolated from said coupling part and is magnetically coupled to said coupling part, said antenna part configured to receive power wirelessly from said coupling part, and said antenna part configured to produce an electromagnetic field based on said power that is wirelessly received, said antenna part comprising a capacitor integrated thereon, and said antenna part configured to resonate at said first frequency.

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

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

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

5. The transmitter system as in claim 4, wherein said antenna is located on a substrate of PTFE.

6. The transmitter system as in claim 4, wherein said antenna is located on a substrate of PVC.

7. The transmitter system as in claim 4, wherein said antenna is located on a substrate of Rubalit 710.

8. The transmitter system as in claim 4, wherein said antenna is located on a substrate of FR4.

9. The system as in claim 1, wherein said antenna part has an inductive coil loop, said capacitor connected across a portion of said inductive coil loop.

10. The system as in claim 9, further comprising a cube shaped housing in which said capacitor is housed.

11. The system as in claim 9, wherein said antenna has two turns in the coil loop.

12. The system as in claim 1, wherein said antenna part has a single turn in the coil loop.

13. The system as in claim 1, wherein said antenna part has a quality factor that is a ratio of a resonant frequency of the antenna part to a half power bandwidth of the antenna part.

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

15. The system as in claim 1, further comprising an attachment part extending between distal edges of material which defines a loop, said attachment part including a vacuum capacitor.

16. The transmitter system as in claim 1, wherein said first frequency is 13.56 MHz.

17. The system as in claim 1, wherein the antenna part has an antenna resistance, and wherein the antenna resistance is equal to a value based on the internal resistance of the signal generator to maximize power transferred from the transmitter to a receiver.

18. The system as in claim 17, wherein the antenna resistance is matched to the resistance of the signal generator.

19. A system for transmitting electrical power via a wireless field, comprising:

a source configured to produce an output electrical signal having a first frequency;

an antenna part configured to create an electromagnetic field based on said power that is wirelessly received, said antenna part comprising a capacitor integrated thereon, said antenna part being substantially resonant at said first frequency; and

a receiver configured to receive the electrical power, where the receiver includes;

a resonant antenna that is tuned to said first frequency; and

a non-resonant coupling part, spaced from said antenna, such that said coupling part is galvanically isolated from said antenna and is magnetically coupled to said antenna, said coupling part configured to receive a signal having said first frequency from said antenna, and said coupling part configured to produce a power output based on the received signal.

20. The system as in claim 19, wherein the receiver has a quality factor value that is lower than a quality factor value of the antenna part.

21. The system as in claim 19, wherein the receiver has a quality factor that is equal to or less than one quarter of the quality factor of the antenna part.

22. The system as in claim 19, wherein the receiver antenna has footprint that is smaller than a footprint of the antenna part.

23. The system as in claim 19, wherein the antenna part and receiver antenna are configured to be coupled with one another to form an energy link that is operative like a loosely coupled transformer.

24. A receiver system for receiving electrical power via an electromagnetic field, comprising:

a resonant antenna part, configured to receive power via the electromagnetic field, said antenna part comprising a capacitor integrated thereon, the antenna part being substantially resonant at a first frequency; and

a non-resonant coupling part, spaced from said antenna part, such that said coupling loop is galvanically isolated from said antenna part and is magnetically coupled to said antenna part, said coupling part configured to receive a signal having said first frequency from said antenna part, and said coupling part configured to produce a power output based on the received signal.

25. The system as in claim 24, further comprising an electrical circuit configured to receive said power output and said electrical circuit further configured to produce output power based on the received power output.

26. The system as in claim 25, wherein said antenna part has a quality factor greater than 500.

27. The system as in claim 25, wherein said antenna part is located on a substrate that supports said antenna part, and said substrate has a quality factor which is greater than 500.

28. The system as in claim 26, wherein said antenna part comprises an integral capacitor made from a vacuum capacitor.

29. The system as in claim 26, wherein said antenna part comprises an inductive coil loop, and a capacitor connected across a portion of said inductive coil loop.

30. The system as in claim 29, further comprising a cube shaped housing in which said capacitor is housed.

31. The system as in claim 29, wherein said antenna part has a single turn in the coil loop.

32. The system as in claim 29, wherein said antenna has two turns in the coil loop.

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

34. The system as in claim 33, wherein the antenna part has a quality factor value that is lower than a quality factor value of the transmitter.

35. The system as in claim 33, wherein the transmitter has a quality factor that is equal to or less than one quarter of the quality factor of the transmitter.

36. The system as in claim 33, wherein the antenna part has a footprint that is smaller than a footprint of the transmitter antenna.

37. The system as in claim 33, wherein the transmitter antenna and receiver antenna part are configured to be coupled with one another to form an energy link that operates as a loosely coupled transformer.

38. The system as in claim 33, wherein said quality factor is a ratio of a resonant frequency of the antenna part to a half power bandwidth of the antenna part.

39. The system as in claim 33, wherein said capacitor has a Q of at least 1000.

40. The system as in claim 33, wherein said capacitor is a vacuum capacitor.

41. The receiver as in claim 24, wherein said first frequency is 13.56 Mhz.

42. The receiver as in claim 24, wherein said antenna is located on a substrate of PTFE.

43. The receiver as in claim 24, wherein said antenna is located on a substrate of PVC.

44. The receiver as in claim 24, wherein said antenna is located on a substrate of Rubalit 710.

45. The receiver as in claim 24, wherein said antenna is located on a substrate of FR4.

46. The system as in claim 24, wherein the coupling loop is connected to a load and is configured to transfer power to the load, wherein the antenna part has an antenna resistance, and wherein the antenna resistance is equal to a value based on the resistance of the load to maximize power transferred to the load.

47. The system as in claim 46, wherein the antenna resistance is matched to the resistance of the load.

48. A method, comprising:

producing a magnetic field at a first frequency based on applied power using a non-resonant loop antenna; and

coupling a portion of the power, via a wireless field, between said non-resonant loop antenna and a resonant loop antenna that is gavanically isolated from said non-resonant loop antenna and magnetically coupled to the non-resonant loop antenna, where said resonant loop antenna comprises a capacitor integrated thereon, and where said resonant loop antenna has a resonant value at said first frequency.

49. The method as in claim 48, wherein said non-resonant and resonant loop antennas are both transmit antennas.

50. The method as in claim 48, wherein said coupling comprises coupling using a loosely-coupled transformer coupling.

51. The method as in claim 48, wherein the first loop antenna has an antenna resistance, and wherein the antenna resistance is equal to a value based on the internal resistance of a signal generator to maximize power transferred from a transmitter to a receiver.

52. The method as in claim 51, wherein the antenna resistance is matched to the resistance of the signal generator.

53. A method, comprising:

receiving power via an electromagnetic field at a first frequency based on applied power using a resonant loop antenna comprising a capacitor integrated thereon, from a non-resonant loop antenna that is associated with said resonant loop antenna, and where said resonant loop antenna and said non-resonant loop antenna are galvanically isolated from one another, and where said non-resonant loop antenna has no separate capacitor attached thereto, and where said non-resonant loop antenna is configured to receive a signal having said first frequency from said resonant loop antenna; and

transmitting a portion of the power received via the electromagnetic field between said resonant loop antenna and said non-resonant loop antenna; and

rectifying an output from said non-resonant loop antenna to produce a DC output.

54. The method as in claim 53, wherein said first and second loop antennas are both receive antennas.

55. The method as in claim 53, wherein said coupling comprises coupling using a loosely-coupled transformer coupling.

56. The method as in claim 53, further comprising transferring power to a load with the second loop antenna, wherein the second loop antenna has an antenna resistance, and wherein the antenna resistance is equal to a value based on the resistance of the load to maximize power transferred to the load.

57. The method as in claim 56, wherein the antenna resistance is matched to the resistance of the load.

58. A transmitter system for transmitting electrical power via a wireless field, comprising:

a source configured to produce an output electrical signal having a first frequency;

a non-resonant coupling part, physically connected to said source, said coupling part comprising multiple loops of wire; and

a resonant antenna part, spaced from said coupling part such that said antenna part is galvanically isolated from said coupling part and is magnetically coupled to said coupling part, said antenna part receiving power wirelessly from said coupling part, and said antenna part producing an electromagnetic field based on said power that is wirelessly received, said antenna part comprising a capacitor integrated thereon, and said antenna part configured to resonate at said first frequency.

59. The transmitter system as in claim 58, wherein said multiple loops of wire are impedance matched to the source.

60. The system as in claim 58, wherein said antenna part has a quality factor greater than 500.

61. The system as in claim 58, wherein said antenna part is formed with an integral capacitor comprising a vacuum capacitor.

62. The system as in claim 58, wherein said antenna part comprises an inductive coil loop and a capacitor connected across a portion of said inductive coil loop.

63. The system as in claim 62, wherein said antenna part comprises a single turn in the inductive coil loop.

64. The system as in claim 62, wherein said antenna comprises two turns in the inductive coil loop.

65. The system as in claim 58, further comprising a receiver for the electrical power, where the receiver includes an antenna that is tuned to said first frequency.

66. The system as in claim 65, wherein the receiver has a quality factor value that is lower than a quality factor value of the antenna part.

67. The system as in claim 65, wherein the receiver has a quality factor that is equal to or less than one quarter of the quality factor of the antenna part.

68. The system as in claim 65, wherein the receiver antenna has a footprint that is smaller than a footprint of the antenna part.

69. The system as in claim 65, wherein the transmitter antenna and receiver antenna coupled to one another in order to form energy link that is operative like a loosely coupled transformer.

70. The system as in claim 58, wherein the antenna part has an antenna resistance, and wherein the antenna resistance is equal to a value based on the internal resistance of the signal generator to maximize power transferred from the transmitter to a receiver.

71. The system as in claim 70, wherein the antenna resistance is matched to the resistance of the signal generator.

72. A receiver system for receiving electrical power via an electromagnetic field, comprising:

a resonant antenna part, configured to receive power via the electromagnetic field, said antenna part comprising a capacitor integrated thereon and configured to be substantially resonant with a first frequency; and

a non-resonant coupling part, spaced from said antenna part, such that said coupling part is galvanically isolated from said antenna part and is magnetically coupled to said antenna part, said coupling part formed of multiple turns of wire, and said coupling part configured to receive a signal having said first frequency from said antenna part, and producing a power output based on the received signal.

73. The system as in claim 72, further comprising an electrical circuit configured to receive said power output, said electrical circuit further configured to produce output power based on the received power output.

74. The system as in claim 72, wherein said antenna part has a quality factor greater than 500.

75. The system as in claim 72, 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.

76. The system as in claim 72, wherein said antenna part comprises a coil loop having a single turn.

77. The system as in claim 72, wherein said antenna comprises a coil loop having a two turns.

78. The system as in claim 72, further comprising a transmitter configured to transmit the electrical power, where the transmitter includes an antenna that is tuned to said first frequency.

79. The system as in claim 78, wherein the antenna part has a quality factor value that is lower than a quality factor value of the transmitter.

80. The system as in claim 78, wherein the antenna part has a quality factor that is equal to or less than one quarter of the quality factor of the transmitter.

81. The system as in claim 78, wherein the antenna part has a footprint that is smaller than a footprint of the transmitter antenna.

82. A system as in claim 72, wherein the coupling part is connected to a load and is configured to transfer power to the load, wherein the antenna part has an antenna resistance, and wherein the antenna resistance is equal to a value based on the resistance of the load to maximize power transferred to the load.

83. The system as in claim 82, wherein the antenna resistance is matched to the resistance of the load.

84. A method, comprising:

producing a magnetic field at a first frequency based on applied power using a non-resonant loop antenna formed of multiple loops of wire, the non-resonant loop antenna including no separate capacitor attached thereto; and

coupling a portion of the power, via a wireless field, between said non-resonant loop antenna and a resonant loop antenna associated with the non-resonant loop antenna, where said resonant loop antenna comprising a capacitor integrated thereon, and where said resonant loop antenna has a resonant value at said first frequency.

85. A wireless electrical power system, comprising:

a transmitter, comprising;

a source configured to produce an output electrical signal having a first frequency,

a non-resonant coupling part, physically connected to said source, said coupling part comprising a first loop of wire, and

a non-resonant antenna part spaced from said coupling part such that said antenna part is galvanically isolated from said coupling part and is magnetically coupled to said coupling part, said antenna part wirelessly receiving power from said coupling part and said antenna part producing an electromagnetic field based on said power that is wirelessly received, said antenna part comprising a capacitor integrated thereon, and said antenna part having an LC value which is substantially resonant with said first frequency; and

a receiver configured to receive the electrical power, where the receiver includes an antenna that is tuned to said first frequency,

wherein the receiver has a quality factor value that is lower than a quality factor value of the transmitter.

86. The system as in claim 85, wherein said coupling part comprises multiple turns.

87. The system as in claim 85, wherein said antenna part comprises a coil loop having a single turn.

88. The system as in claim 85, wherein said antenna part comprises a coil loop having two turns.

89. The system as in claim 85, wherein the receiver has a quality factor that is equal to or less than one quarter of the quality factor of the transmitter.

90. The system as in claim 85, wherein the receiver antenna has a footprint that is smaller than a footprint of the transmitter antenna.

91. A system for transmitting power, comprising:

a source configured to produce an output electrical signal having a first frequency;

a resonant antenna part configured to produce an electromagnetic field for transferring power to a receiver, the antenna part having a capacitor integrated thereon, the antenna part configured to resonate at said first frequency; and

non-resonant means for receiving the output electrical signal from the source and transferring power to the antenna part, via an electromagnetic field, the means for receiving the output electrical signal being physically connected to the source and magnetically coupled to the antenna part.

92. The system as in claim 91, wherein the means for receiving the output electrical signal comprises a coupling loop.

93. A system for receiving power comprising:

a resonant antenna part configured to receive power, via an electromagnetic field, at a first frequency, the antenna part configured to resonate at said first frequency;

non-resonant means for receiving power, via an electromagnetic field at said first frequency, from the antenna part, the means for receiving power configured to be magnetically coupled with the antenna part; and

means for rectifying an output received from the means for receiving power to produce a DC output.