Planar anti-reflective interference antennas with extra-planar element extensions

• US 7,333,068 B2
• Filed: 11/15/2005
• Issued: 02/19/2008
• Est. Priority Date: 11/15/2005
• Status: Expired due to Fees

• Current Assignee: Clearone Incorporated
• Original Assignee: ClearOne Communications Inc. (Clearone Incorporated)
• Inventors: Biddulph, Stuart
• Primary Examiner(s): Owens; Douglas W.
• Assistant Examiner(s): Tran; Chuc
• Application Number:
  US11/274,644
• Publication Number:
  US 20070109194A1
• Time in Patent Office: 826 Days
• Field of Search: 343/844, 343/810, 343/814, 343/872, 343/834, 343/836, 343/793, 343/795, 343/853, 343/846
• US Class Current: 343/794
• CPC Class Codes: H01Q 21/20 the units being spaced along or adjacent to a curvilinear path slotted waveguide arrays H01Q21/005; circularly or helically slotted waveguides H01Q21/0062
• CPC Class Codes: H01Q 21/205 providing an omnidirectional coverage turnstile aerials H01Q21/26
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence

Abstract

Disclosed herein are wireless products adapted to be positioned in a normal or resting position, that also include an antenna composed of a set of elements arranged in a plane in a radially symmetrical configuration providing a reduction in the susceptibility of reflected waves having the potential to cancel or weaken a main wave or signal, the plane positioned with respect to the normal position to direct a main communication line with a second wireless device into the plane and provide reception of a main and/or secondary signal at a plurality of phases. One exemplary product is a wireless conferencing device configured to rest on a tabletop, the antenna array oriented in a horizontal plane. Detailed information on various example embodiments of the inventions are provided in the Detailed Description below, and the inventions are defined by the appended claims.

Claims

1. A radio antenna array for use at a design frequency having reflective immunity properties, comprising:

a rigid planar structure, said structure defining a plane;

a first antenna element;

a second antenna element located a distance from said first antenna element providing an amount of phase difference for a signal traveling in a first direction passing through said first antenna element and said second antenna element;

a third antenna element located a distance from said first antenna element providing an amount of phase difference for a signal traveling in a second direction passing through said first antenna element and said third antenna element, whereby the second direction is different than the first direction;

transmission lines providing an electrical connection from said first, second and third antenna elements to a combiner;

wherein said first, second and third antenna elements are located in said plane; and

wherein said first, second and third antenna elements each incorporate a conductive element extension that includes a portion extending out of said plane.

2. An antenna array according to claim 1, wherein the centers of said first, second and third antenna elements are positioned at the corners of an equilateral triangle.

3. An antenna array according to claim 1, wherein the array presents at least two elements at a phase difference of other than one-half wavelength at the design frequency.

4. An antenna array according to claim 1, wherein said array is resonant at the design frequency.

5. An antenna array according to claim 1, wherein each of said extensions is formed as a shaft-like structure rising from the antenna element surface.

6. An antenna array according to claim 1, wherein each of said extensions is formed as a blade.

7. An antenna array according to claim 6, wherein each of said blade extensions is oriented in the same direction as current travel in its connected antenna element.

8. An antenna array according to claim 1, wherein said neither of said transmission lines or said combiner include switches, sensors or control algorithms.

9. An antenna array according to claim 8, wherein under conditions of receiving a main signal in an undetermined direction and a reflecting interfering signal randomly oriented to the main signal, both of those signals being in the plane of said antenna array and received at said array at equal strength, the probability of destructive interference exceeding 10 dB is less than for a theoretical monopole antenna.

10. An antenna array according to claim 9, wherein the probability of destructive interference exceeding 10 dB is equal to or less than about two percent.

11. An antenna array according to claim 9, wherein the probability of destructive interference exceeding 10 dB is equal to or less than about one percent.

12. An antenna array according to claim 9, wherein the probability of destructive interference exceeding 10 dB is equal to about one-half percent.

13. An antenna array according to claim 8, wherein the destructive effects of a reflectively interfering signal incident on said array in an angle to its main signal can be reduced by rotating said array.

18. An antenna array according to claim 1, wherein the centers of said first, second and third antenna elements are positioned at the corners of an equilateral triangle.

19. An antenna array according to claim 1, wherein the array presents at least two elements at a phase difference of other than one-half wavelength at the design frequency.

20. An antenna array according to claim 1, wherein said array is resonant at the design frequency.

21. An antenna array according to claim 1, wherein each of said extensions is formed as a shaft-like structure rising from the antenna element surface.

22. An antenna array according to claim 1, wherein each of said extensions is formed as a blade.

23. An antenna array according to claim 22, wherein each of said blade extensions is oriented in the same direction as current travel in its connected antenna element.

14. A radio antenna array for use at a design frequency having reflective immunity properties, comprising:

a layer, said layer defining a plane;

a first antenna element;

a second antenna element located a distance from said first antenna element providing an amount of phase difference for a signal traveling in a first direction passing through said first antenna element and said second antenna element;

a third antenna element located a distance from said first antenna element providing an amount of phase difference for a signal traveling in a second direction passing through said first antenna element and said third antenna element, whereby the second direction is different than the first direction;

transmission lines providing an electrical connection from said first, second and third antenna elements to a combiner;

wherein said first, second and third antenna elements are located in said plane; and

wherein said first, second and third antenna elements each incorporate a conductive element extension that includes a portion extending out of said plane.

15. An antenna array according to claim 14, wherein the feed impedance is kept equal in said transmission lines between said combiner and said first, second and third antenna elements.

16. An antenna array according to claim 14, wherein in each of said transmission lines an equal propagation delay is maintained.

17. An antenna array according to claim 14, farther comprising a ground plane layer.

24. An antenna array according to claim 14, wherein said neither of said transmission lines or said combiner include switches, sensors or control algorithms.

25. An antenna array according to claim 24, wherein under conditions of receiving a main signal in an undetermined direction and a reflecting interfering signal randomly oriented to the main signal, both of those signals being in the plane of said antenna array and received at said array at equal strength, the probability of destructive interference exceeding 10 dB is less than for a theoretical monopole antenna.

26. An antenna array according to claim 25, wherein the probability of destructive interference exceeding 10 dB is equal to or less than about two percent.

27. An antenna array according to claim 25, wherein the probability of destructive interference exceeding 10 dB is equal to or less than about one percent.

28. An antenna array according to claim 25, wherein the probability of destructive interference exceeding 10 dB is equal to about one-half percent.

29. An antenna array according to claim 24, wherein the destructive effects of a reflectively interfering signal incident on said array in a substantial angle to its main signal can be reduced by rotating said array.

30. A radio antenna array for use at a design frequency having reflective immunity properties, comprising:

a printed circuit board including at least one layer;

a first antenna element;

a second antenna element located a distance from said first antenna element providing an amount of phase difference for a signal traveling in a first direction passing through said first antenna element and said second antenna element;

a third antenna element located a distance from said first antenna element providing an amount of phase difference for a signal traveling in a second direction passing through said first antenna element and said third antenna element, whereby the second direction is different than the first direction;

transmission lines providing an electrical connection from said first, second and third antenna elements to a combiner;

wherein said first, second and third antenna elements each incorporate a conductive element extension that includes a portion extending out of said plane; and

wherein said first, second and third antenna elements are incorporated to said layer.

31. An antenna array according to claim 30, wherein the feed impedance is kept equal in said transmission lines between said combiner and said first, second and third elements.

32. An antenna array according to claim 30, wherein in each of said transmission lines an equal propagation delay is maintained.

33. An antenna array according to claim 30, further comprising a ground plane layer.

34. An antenna array according to claim 30, wherein the centers of said first, second and third antenna elements are positioned at the corners of an equilateral triangle.

35. An antenna array according to claim 30, wherein the array presents at least two elements at a phase difference of other than one-half wavelength at the design frequency.

36. An antenna array according to claim 30, wherein said array is resonant at the design frequency.

37. An antenna array according to claim 30, wherein each of said extensions is formed as a shaft-like structure rising from the antenna element surface.

38. An antenna array according to claim 30, wherein each of said extensions is formed as a blade.

39. An antenna array according to claim 38, wherein each of said blade extensions is oriented in the same direction as current travel in its connected antenna element.

40. An antenna array according to claim 30, wherein said neither of said transmission lines or said combiner include switches, sensors or control algorithms.

41. An antenna array according to claim 40, wherein under conditions of receiving a main signal in an undetermined direction and a reflecting interfering signal randomly oriented to the main signal, both of those signals being in the plane of said antenna array and received at said array at equal strength, the probability of destructive interference exceeding 10 dB is less than for a theoretical monopole antenna.

42. An antenna array according to claim 41, wherein the probability of destructive interference exceeding 10 dB is equal to or less than about two percent.

43. An antenna array according to claim 41, wherein the probability of destructive interference exceeding 10 dB is equal to or less than about one percent.

44. An antenna array according to claim 41, wherein the probability of destructive interference exceeding 10 dB is equal to about one-half percent.

45. An antenna array according to claim 40, wherein the destructive effects of a reflectively interfering signal incident on said array in an angle to its main signal can be reduced by rotating said array.