System and method for improving antenna pattern with a TE20 mode waveguide

• US 20040217913A1
• Filed: 04/29/2003
• Published: 11/04/2004
• Est. Priority Date: 04/29/2003
• Status: Active Grant

• Current Assignee: BWA Technology Incorporated
• Original Assignee: Harris Broadband Wireless Access Incorporated
• Inventors: McCandless, Jay
• Granted Patent: US 6,914,577 B2
• Time in Patent Office: Days
• US Class Current: 343/841
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 1/521 reducing the coupling between adjacent antennas
• CPC Class Codes: H01Q 13/0266 provided with a flange or a choke

Abstract

An isolation shield improves the F/B ratio for a directional antenna radiating a electromagnetic wave with a wavelength of λ_XMT with a TE₂₀ mode waveguide. The system includes a directional antenna and a waveguide adapted for attachment to one side of the directional antenna. The waveguide defines a channel spanning and positioned adjacent to the side of the directional antenna. The channel has a width and depth that are functions of λ_XMT. The waveguide excites a null in the E-field within the channel. The null being adjacent to the edge of the directional antenna and thereby improving the F/B ratio of the directional antenna.

Claims

1. An isolation shield for improving F/B ratio for a directional antenna radiating a electromagnetic wave with a wavelength of λ

, comprising;

a waveguide adapted for attachment to at least one side of the directional antenna, said waveguide defining a channel spanning along and positioned adjacent to said at least one side of the directional antenna;

wherein a width of the channel is a function of λ

; and

,

wherein the channel excites a null E field adjacent to said at least one side, thereby improving the F/B ratio of the directional antenna.

2. The isolation shield of claim 1, wherein the channel width is between 1.05 λ

and 1.4 λ

.

3. The isolation shield of claim 1, wherein the electromagnetic wave radiated by the directional antenna is horizontally polarized.

4. The isolation shield of claim 1, wherein the electromagnetic wave radiated by the directional antenna is vertically polarized.

5. The isolation shield of claim 1, wherein the electromagnetic wave radiated by the directional antenna has a frequency between 1 and 100 GHz

6. The isolation shield of claim 1, wherein the directional antenna is a panel antenna.

7. The isolation shield of claim 1, wherein the directional antenna is a horn antenna.

8. The isolation shield of claim 1, wherein the directional antenna is a dish antenna.

9. The isolation shield of claim 1, wherein a depth of the channel is between 1.05 λ

and 1.4 λ

.

10. The isolation shield of claim 2, wherein a depth of the channel is equal to the width of the channel.

11. The isolation shield of claim 1, wherein the channel spans along parallel to at least a portion of one side of the directional antenna.

12. A directional antenna system configured for radiating a signal at c/λ

hertz comprising;

a directional antenna defined by an outer edge for radiating the signal;

a waveguide adjacent to at least a portion of the outer edge;

said waveguide forming a channel adjacent to the at least a portion of the outer edge; and

,

wherein the waveguide is dimensioned to excite a TE₂₀ mode at an wavelength λ

within the channel.

13. The directional antenna system of claim 12, the channel having a channel width and a channel depth, said channel width between 1.05 λ

and 1.4 λ

.

14. The directional antenna system of claim 12, wherein the signal is horizontally polarized.

15. The directional antenna system of claim 12, wherein the signal is vertically polarized.

16. The directional antenna system of claim 12, wherein the signal is between 1 and 100 GHz.

17. The directional antenna system of claim 12, wherein the directional antenna is a panel antenna.

18. The directional antenna system of claim 12, wherein the directional antenna is a horn antenna.

19. The directional antenna system of claim 12, wherein the directional antenna is a dish antenna.

20. The directional antenna system of claim 12, wherein the channel having a channel width and a channel depth, said channel depth between 1.05 λ

and 1.4 λ

.

21. The directional antenna system of claim 13, wherein the channel depth is equal to the channel width.

22. The directional antenna system of claim 12, wherein the channel defined by the waveguide is parallel to the at least a portion of the outer edge.

23. A method for improving the F/B ratio for a directional antenna with an adjacent waveguide, wherein the directional antenna is configured to radiate a λ

wavelength signal, the improvement comprising dimensioning the waveguide to excite a TE₂₀ mode for the λ

wavelength signal and creating a null, along an edge of the direction antenna, in an E-field leaked from the antenna, thereby improving the F/B ratio of the directional antenna.

24. The method of claim 23, wherein the waveguide defines a channel, the channel having a channel width and a channel depth, said channel width between 1.05 λ

and 1.4 λ

.

25. The method of claim 23, wherein the λ

wavelength signal is horizontally polarized.

26. The method of claim 23, wherein the λ

wavelength signal is vertically polarized.

27. The method of claim 23, wherein the λ

wavelength signal is between 1 and 200 GHz.

28. The method of claim 23, wherein the directional antenna is a panel antenna.

29. The method of claim 23, wherein the directional antenna is a horn antenna.

30. The method of claim 23, wherein the directional antenna is a dish antenna.

31. The method of claim 23, wherein the waveguide defines a channel, the channel having a channel width and a channel depth, said channel depth is between 1.05 λ

and 1.4 λ

.

32. The method of claim 24, wherein the channel depth is equal to the channel width.

33. The method of claim 23, comprising the step of orienting a channel defined by the waveguide parallel to at least a portion of the edge.

34. An antenna cluster having at least two co-located directional antenna systems, one of the at least two co-located antenna systems is configured for radiating a c/λ

₁ hertz signal in one direction and another of the at least two co-located antennas systems is configured for radiating a c/λ

₂ hertz signal in another direction, wherein said one of the at least two co-located antennas systems comprises;

a directional antenna defined by an outer edge;

a waveguide adjacent to at least a portion of the outer edge;

wherein the waveguide is dimensioned to excite a TE₂₀ mode at an wavelength λ

₂ within the waveguide.

35. The antenna cluster of claim 34, wherein the waveguide defines a channel, the channel having a channel width and a channel depth, said channel width between 1.05 λ

and 1.4 λ

.

36. The antenna cluster of claim 34, wherein the signal is horizontally polarized.

37. The antenna cluster of claim 34, wherein the signal is vertically polarized.

38. The antenna cluster of claim 34, wherein the signal is between 1 and 100 GHz.

39. The antenna cluster of claim 34, wherein the directional antenna is a panel antenna.

40. The antenna cluster of claim 34, wherein the directional antenna is a horn antenna.

41. The antenna cluster of claim 34, wherein the directional antenna is a dish antenna.

42. The antenna cluster of claim 34, wherein the waveguide defines a channel, the channel having a channel width and a channel depth, said channel depth is between 1.05 λ

and 1.4 λ

.

43. The antenna cluster of claim 35, wherein the channel depth is equal to the channel width.

44. The antenna cluster of claim 34, wherein a channel defined by the waveguide is parallel to at least a portion of the outer edge.

45. A directional antenna system configured for radiating a horizontally polarized signal with at c/λ

hertz comprising;

a directional panel antenna defined by an outer edge for radiating the signal, said outer edge formed by two side edges, a top edge and a bottom edge

a waveguide adjacent one of the two side edges;

said waveguide forming a channel parallel to said one of the two side edges;

wherein the waveguide is dimensioned to excite a TE₂₀ mode within said channel for a λ

wavelength.

46. The directional antenna system of claim 45, wherein said channel is defined by a first second and third conductive surfaces, said first and second conductive surfaces parallel to each other and perpendicular to the third conductive surface.

47. The directional antenna system of claim 45, wherein a channel width is between 1.05 λ

and 1.4 λ

.

48. The directional antenna system of claim 45, wherein a channel depth is between 1.05 λ

and 1.4 λ

.

49. The directional antenna system of claim 47, wherein a channel depth and the channel width are approximately equal.

50. The directional antenna system of claim 45, wherein the signal is between 1 and 100 GHz.