Low cost multi-beam, multi-band and multi-diversity antenna systems and methods for wireless communications

• US 7,525,504 B1
• Filed: 06/30/2006
• Issued: 04/28/2009
• Est. Priority Date: 11/24/2003
• Status: Active Grant

• Current Assignee: Hong Kong Applied Science And Technology Research Institute Co., Ltd.
• Original Assignee: Hong Kong Applied Science And Technology Research Institute Co., Ltd.
• Inventors: Wong, Piu Bill, Murch, Ross David, Song, Peter Chun Teck, George, Douglas Ronald, Keung, Angus Mak Chi
• Primary Examiner(s): DINH, TRINH VO
• Application Number:
  US11/480,317
• Time in Patent Office: 1,033 Days
• Field of Search: None
• US Class Current: 343/850
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 25/005 providing two patterns of opposite direction; back to back antennas H01Q25/004 takes precedence

Abstract

Systems and methods for employing switched phase shifters and a feed network to provide a low cost multiple beam antenna system for wireless communications. The present systems and methods may also facilitate multi-band communications and employ multi-diversity. The present systems and methods allow communication systems to achieve enhanced performance for communication or other services such as location tracking. The present systems and methods may employ switched phase shifters, multiple diversity antennas and/or a feed network having a multi-layer construction to provide an antenna system with low losses, low external component count and/or which is thin and compact.

Claims

1. A low cost adaptive multi-beam and multi-diversity antenna array comprising:

a plurality of antenna elements, said elements simultaneously providing a plurality of beams, each of said beams selectively having diverse characteristics;

an integrated feed network feeding said elements from an input and providing adaptive beam forming for said plurality of beams, said feed network comprising switched phase shifters that are digitally controlled, wherein each switched phase shifter includes a plurality of phase shift lines; and

a plurality of meander line inductors to reduce loss in the array, wherein each of said meander lines is associated with one of the plurality of phase shift lines.

2. The array of claim 1 wherein said array is defined within a panel.

3. The array of claim 1 wherein said feed network is defined on a printed circuit board.

4. The array of claim 1 wherein said feed network employs diodes as switches.

5. The array of claim 4 wherein said diodes are disposed in said phases shifters in a back-to-back configuration.

6. The array of claim 5 wherein said diodes are PIN diodes.

7. The array of claim 1 wherein said array is multi-band.

8. The array of claim 7 wherein the bands share an aperture.

9. The array of claim 7 wherein elements for different bands are interleaved.

10. The array of claim 1 wherein said array is broadband.

11. The array of claim 1 wherein said elements are arranged to provide reduced coupling.

12. The array of claim 1 wherein said elements comprise patch antenna elements.

13. The array of claim 12 wherein said patch elements comprise stacked patch antenna elements.

14. The array of claim 12 wherein said antenna elements comprise diversity monopole elements.

15. The array of claim 14 wherein said diversity monopole elements comprise a monopole feed element and a ground providing a differential path.

16. The array of claim 15 wherein said ground is a ground plane supporting said feed network.

17. The array of claim 1 wherein said antenna elements comprise slot integrated patch antenna elements.

18. The array of claim 17 wherein said slot integrated patch antenna elements are feed to provide branch diversity.

19. The array of claim 17 wherein said slot integrated patch antenna elements are feed to provide polarization diversity.

20. The array of claim 17 wherein said slot integrated patch antenna elements are feed to provide branch diversity and polarization diversity.

21. The array of claim 1 wherein each of said antenna elements comprise an integrated magnetic dipole and electric dipole.

22. The array of claim 21 wherein said magnetic dipole is provided by slots defined in grounded material.

23. The array of claim 22 wherein said electric dipole is disposed in said slots.

24. The array of claim 1 wherein spacing of said elements is optimized for scanning angle and gain.

25. The array of claim 24 wherein optimal element spacing is 0.64 wavelengths.

26. The array of claim 1 wherein said array is disposed on a flat surface.

27. The array of claim 1 wherein said array is disposed on a curved surface.

28. The array of claim 1 wherein panels making up said array are disposed at angels relative to one another to define a curved array.

29. The array of claim 1 further comprising directors extending a scanning angle of said array.

30. The array of claim 29 wherein a printed circuit board defining said feed network and supporting said elements support said directors.

31. The array of claim 29 wherein a ground plane reflector disposed behind said elements does not extend behind said directors, thereby aiding steering of beams along a plane of said array.

32. The array of claim 1 wherein said phase shifters define a plurality of line lengths to provide phase shifts by switching between said lines.

33. The array of claim 32 wherein said line lengths are provided by reduced size phase shift lines.

34. The array of claim 33 wherein ones of said reduced size phase shift lines are combined in paths through a phase shifter to provide desired phase shift paths.

35. The array of claim 32 wherein said phase shifts are discrete.

36. The array of claim 32 further comprising diodes disposed in line lengths to provide isolation of between said lines.

37. The array of claim 36 further comprising diodes disposed in line lengths, spaced apart from junctions of said line lengths to provide isolation between said lines.

38. The array of claim 36 further comprising diodes disposed in line lengths, spaced apart from junctions of said line lengths to prevent opposite phased power leakage cancellation between different ones of said lines.

39. The array of claim 36 further comprising diodes disposed in line lengths, spaced apart from junctions of said line lengths to cancel resonance effects in said lines.

40. The array of claim 1 wherein said feed network feeds said elements in two orthogonal branches.

41. The array of claim 40 wherein said feed network comprises a phase shifter to provide two orthogonal phases and a switch to selectively feed one of said orthogonal branches.

42. The array of claim 1 wherein said feed network comprises differential feeds for said elements.

43. The array of claim 42 wherein said differential feeds for said elements provide signals to said element 180 degrees out of phase.

44. The array of claim 1 further comprising controls having fault detection provided by current sensing to assess the current drawn by said phases shifters of said feed network to determine proper operation of said feed network phase shifters.

45. The array of claim 1, wherein each phase shift line has a delay selected from the group consisting of:

0 degrees, 90 degrees, 180 degrees, and 270 degrees.

46. The array of claim 1, wherein the phase shifters are controlled to select one of a plurality of beam patterns for the array.

47. The array of claim 1, wherein the plurality of antenna elements and said feed network, at least in part, formed on a same printed circuit board.

48. The array of claim 1, wherein the beams are used for at least one of improve coverage of the array in one direction, enhancing location estimation using the array, and tracking an object using the array.

49. A low cost adaptive multi-beam and multi-diversity antenna array comprising:

a plurality of antenna elements, said elements providing a plurality of beams, each of said beams selectively having diverse characteristics;

an integrated feed network feeding said elements from an input and providing adaptive beam forming for said plurality of beams, said feed network comprising switched phase shifters wherein each switched phase shifter includes a plurality of phase shift lines;

a reflector positioned behind said elements, and

a plurality of meander line inductors to reduce loss in the array, wherein each of said meander lines is associated with one of the plurality of phase shift lines.

50. The array of claim 49 wherein said reflector is a ground plane.

51. The array of claim 49, wherein each phase shift line has a delay selected from the group consisting of:

0 degrees, 90 degrees, 180 degrees, and 270 degrees.

52. The array of claim 49, wherein said elements simultaneously provide the plurality of beams.

53. The array of claim 49, wherein said phase shifters are digitally controlled.

54. The array of claim 49, wherein the phase shifters are controlled to select one of a plurality of beam patterns for the array.

55. The array of claim 49, wherein the plurality of antenna elements and said feed network, at least in part, formed on a same printed circuit board.

56. The array of claim 49, wherein the beams are used for at least one of improve coverage of the array in one direction, enhancing location estimation using the array, and tracking an object using the array.

57. A method for adaptively providing multiple antenna beams having multi-diversity at low cost, said method comprising:

feeding a plurality of antenna elements with a switched phase shifter feed network that is digitally controlled, wherein the network includes a plurality of phase delay

simultaneously providing, by said elements, a plurality of antenna beams, each of said beams selectively having diverse characteristics;

providing by said feed network, adaptive beam forming for said plurality of beams; and

providing a plurality of meander line inductors to reduce loss in said plurality of antenna elements, wherein each of said meander lines is associated with one of the plurality of phase shift lines.

58. The method of claim 57 wherein said feeding further comprises employing diodes as switches.

59. The method of claim 58 wherein said employing further comprises disposing said diodes in said phases shifters back-to-back.

60. The method of claim 57 wherein said providing further comprises providing, by said elements, antenna beams of a plurality of bands.

61. The method of claim 60 wherein said bands share an antenna aperture.

62. The method of claim 60 further comprising interleaving elements for different bands.

63. The method of claim 57 further comprising arranging said elements to reduced mutual coupling between elements.

64. The method of claim 57 wherein said elements comprise patch antenna elements.

65. The method of claim 64 wherein said antenna elements comprise diversity monopole elements.

66. The method of claim 65 wherein said diversity monopole elements comprise a monopole feed element and a ground providing a differential path.

67. The method of claim 57 wherein said antenna elements comprise slot integrated patch antenna elements.

68. The method of claim 67 further comprising:

feeding said slot integrated patch antenna elements to provide at least one of branch diversity and polarization diversity.

69. The method of claim 57 wherein each of said antenna elements comprise an integrated magnetic dipole and electric dipole.

70. The method of claim 69 further comprising:

defining slots in grounded material to provide said magnetic dipole.

71. The method of claim 57 further comprising:

optimizing said spacing of said elements for scanning angle and gain.

72. The method of claim 57 further comprising:

providing directors extending a scanning angle of an array comprised of said elements.

73. The method of claim 72 further comprising:

supporting said directors with a printed circuit board defining said feed network and supporting said elements.

74. The method of claim 72 further comprising:

aiding steering of beams along a plane of said array by disposing a ground plane reflector behind said elements to not extend behind said directors.

75. The method of claim 74 further comprising:

providing higher gain and optimizing tuned beam widths using at least one reflector disposed at a termination of said ground plane reflector.

76. The method of claim 57 further comprising:

defining a plurality of line lengths in said phase shifters to provide phase shifts by switching between said lines.

77. The method of claim 76 wherein said line lengths are reduced size phase shift lines.

78. The method of claim 77 further comprising:

combining ones of said reduced size phase shift lines in paths through a phase shifter to provide desired phase shift paths.

79. The method of claim 76 wherein said phase shifts are discrete.

80. The method of claim 76 further comprising:

disposing diodes in said line lengths to provide isolation of between said lines.

81. The method of claim 57 further comprising:

feeding said elements, by said feed network, using two orthogonal branches.

82. The method of claim 81 further comprising:

providing two orthogonal phases using a phase shifter of said feed network; and

selectively switching a feed to one of said orthogonal branches.

83. The method of claim 57 wherein said feed network comprises differential feeds for said elements.

84. The method of claim 83 further comprising:

providing signals to said elements 180 degrees out of phase using said differential feeds for said elements.

85. The method of claim 57 further comprising:

detecting faults in said feed network by sensing current to assess the current drawn by said phases shifters of said feed network, thereby determining proper operation of said feed network phase shifters.

86. The method of claim 57, wherein each phase shift line has a delay selected from the group consisting of:

0 degrees, 90 degrees, 180 degrees, and 270 degrees.

87. The method of claim 57, further comprising:

controlling the phase shifters to select one of a plurality of beam patterns for the antenna elements.

88. The method of claim 57, further comprising:

forming the plurality of antenna elements and said feed network, at least in part, on a printed circuit board.

89. The method of claim 57, further comprising:

using the beams to perform at least one of improving coverage of the antenna elements in one direction, enhancing location estimation, and tracking an object.

90. A method for adaptively providing multiple antenna beams having multi-diversity at low cost, said method comprising:

feeding a plurality of antenna elements with a switched phase shifter feed network;

providing, by said elements, a plurality of antenna beams, each of said beams selectively having diverse characteristics;

providing, by said feed network, adaptive beam forming for said plurality of beams;

defining said plurality of antenna elements and said feed network, at least in part, on a same printed circuit board; and

providing a plurality of meander line inductors to reduce loss in said plurality of antenna elements, wherein each of said meander lines is associated with one of a plurality of phase shift lines of the feed network.

91. The method of claim 90, wherein each phase shift line has a delay selected from the group consisting of:

0 degrees, 90 degrees, 180 degrees, and 270 degrees.

92. The method of claim 90, wherein said elements simultaneously provide the plurality of beams.

93. The method of claim 90, further comprising:

digitally controlling the phase shifter network.

94. The method of claim 90, further comprising:

controlling the phase shifter network to select one of a plurality of beam patterns for the antenna elements.

95. The method of claim 90, further comprising:

using the beams to perform at least one of improving coverage of the antenna elements in one direction, enhancing location estimation, and tracking an object.

96. A method for adaptively providing multiple antenna beams having multi-diversity at low cost, said method comprising:

feeding a plurality of antenna elements with a switched phase shifter feed network;

providing, by said elements, a plurality of antenna beams, each of said beams selectively having diverse characteristics;

providing, by said feed network, adaptive beam forming for said plurality of beams;

providing a reflector that is positioned behind said elements; and

providing a plurality of meander line inductors to reduce loss in said plurality of antenna elements, wherein each of said meander lines is associated with one of a plurality of phase shift lines of the feed network.

97. The method of claim 96 wherein said reflector is a ground plane.

98. The method of claim 96, wherein each phase shift line has a delay selected from the group consisting of:

0 degrees, 90 degrees, 180 degrees, and 270 degrees.

99. The method of claim 96, wherein said elements simultaneously provide the plurality of beams.

100. The method of claim 96, further comprising:

digitally controlling the phase shifter network.

101. The method of claim 96, further comprising:

controlling the phase shifter network to select one of a plurality of beam patterns for the antenna elements.

102. The method of claim 96, further comprising:

forming the plurality of antenna elements and said feed network, at least in part, on a printed circuit board.

103. The method of claim 96, further comprising:

using the beams to perform at least one of improving coverage of the antenna elements in one direction, enhancing location estimation, and tracking an object.