Waveguide for a traveling wave antenna

• US 6,894,654 B2
• Filed: 07/26/2002
• Issued: 05/17/2005
• Est. Priority Date: 09/11/2001
• Status: Expired due to Fees

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: Lynch, Jonathan J.
• Primary Examiner(s): CHEN, SHIH CHAO
• Application Number:
  US10/206,741
• Publication Number:
  US 20030048232A1
• Time in Patent Office: 1,026 Days
• Field of Search: 343/770, 343/771, 343/772, 343/767, 343/785, 343/909
• US Class Current: 343/771
• CPC Class Codes: H01Q 1/32 Adaptation for use in or on road or rail vehicles
• CPC Class Codes: H01Q 13/10 Resonant slot antennas
• CPC Class Codes: H01Q 13/20 Non-resonant leaky-waveguide or transmission-line antennas; Equivalent structures causing radiation along the transmission path of a guided wave
• CPC Class Codes: H01Q 13/22 Longitudinal slot in boundary wall of waveguide or transmission line H01Q13/203 takes precedence
• CPC Class Codes: H01Q 21/005 Slotted waveguides arrays
• CPC Class Codes: H01Q 21/064 using horn or slot aerials slotted waveguides arrays H01Q21/005

Abstract

A travelling waveguide antenna has top and bottom spaced plates, the top plate having radiating apertures extending therethrough. The apertures have inclined surfaces facing one another to provide an outward flare of the apertures.

Claims

1. A waveguide for a travelling wave antenna comprising top and bottom spaced plates and a dielectric uniformly dispersed everywhere between said top and bottom spaced plates, said top plate having radiating apertures extending therethrough, said apertures having inclined surfaces facing one another which provide a flare of said apertures.

2. The waveguide as claimed in claim 1, wherein said thickness of the top plate is equal to about one-quarter of the wavelength of a travelling wave input to the waveguide.

3. The waveguide as claimed in claim 1, wherein the flare of the apertures is between 5 degrees and 90 degrees.

4. The waveguide as claimed in claim 1, wherein the apertures flare outwardly.

5. The waveguide as claimed in claim 1, wherein each aperture has a width at an inner surface of the top plate between 0.01λ

and λ

/2 where λ

is the wavelength of a travelling wave input to the waveguide.

6. The waveguide as claimed in claim 1, wherein said inclined surfaces of said apertures are planar.

7. The waveguide as claimed in claim 1, wherein said inclined surfaces of said apertures are curved.

8. The waveguide as claimed in claim 1, wherein the top and bottom spaced plates are disposed parallel to each other.

9. The waveguide as claimed in claim 1, wherein the top and bottom spaced plates are disposed at an angle to each other, wherein said angle is not 180°

.

10. The waveguide as claimed in claim 1, wherein the top plate has a uniform thickness along its length.

11. The waveguide as claimed in claim 1, wherein said dielectric comprises air.

12. The waveguide as claimed in claim 1, wherein said waveguide has an incident end and each one of said apertures is spaced at increasing distance from said incident end, and each one of said apertures has an inner width and an outer width, wherein said inner width and outer width of each one of said apertures decrease as the distance of each one of said apertures from the incident end increases.

13. In a waveguide of a travelling wave antenna, having top and bottom spaced plates and radiating apertures extending through the top plate, an improvement wherein said apertures are flared and widen from one surface of said top plate to an opposite surface of said top plate.

14. The improvement as claimed in claim 13, wherein said top plate has a thickness equal to about one-quarter of the wavelength of the travelling wave input to said top plate.

15. The improvement as claimed in claim 13, wherein the flare of the apertures is between 5 degrees and 90 degrees.

16. The improvement as claimed in claim 13, wherein said one surface is an inner surface of the top plate and said opposite surface is an outer surface of the top plate and the apertures flare outwardly from the inner surface to the outer surface.

17. The improvement as claimed in claim 13, each aperture has a width at an inner surface of the top plate between 0.01λ

and λ

/2 where λ

is the wavelength of a travelling wave input to the waveguide.

18. The improvement as claimed in claim 13, wherein each aperture has opposite inclined faces which are planar so that the apertures flare linearly.

19. The improvement as claimed in claim 13, wherein each aperture has opposite inclined faces which are curved so that the apertures flare non-linearly.

20. The improvement as claimed in claim 13, wherein the top and bottom spaced plates are disposed parallel to each other.

21. The improvement as claimed in claim 13, wherein the top and spaced plates are disposed at an angle to each other, wherein said angle is not 180°

.

22. The improvement as claimed in claim 13, wherein the space between said top and bottom spaced plates is hollow everywhere between said top and bottom spaced plates.

23. The improvement as claimed in claim 13, wherein the space between said top and bottom spaced plates is uniformly filled with dielectric material.

24. The improvement as claimed in claim 13, wherein said waveguide has an incident end and each one of said radiating apertures is spaced at increasing distance from said incident end, and each one of said apertures has an inner width and an outer width, wherein said inner width and outer width of each one of said apertures decrease as the distance of each one of said apertures from the incident end increases.

25. A method of providing a travelling wave antenna with a low profile height in which the travelling wave antenna has a waveguide with spaced top and bottom conductor plates, the top conductor plate being provided with energy radiating apertures spaced therealong, said method comprising forming said energizing radiating apertures with inclined facing surfaces to form a flare so that said apertures widen from one surface of the top plate to an opposite surface of the top plate and uniformly providing dielectric everywhere between said spaced top and bottom conductor plates.

26. The method as claimed in claim 25, comprising regulating energy radiation through said apertures with determined impedance by providing the apertures with specific widths at said one surface of the top plate and with specific flare angles.

27. The method as claimed in claim 25, wherein said one surface of the top plate is the inner surface and the opposite surface of the top plate is the outer surface, said apertures flaring outwardly in the top plate.

28. The method as claimed in claim 25, wherein said inclined facing surfaces of said apertures are planar.

29. The method as claimed in claim 25, wherein said inclined facing surfaces of apertures are curved.

30. The method as claimed in claim 25, wherein the spaced top and bottom conductor plates are disposed parallel to each other.

31. The method as claimed in claim 25, wherein the spaced top and bottom conductor plates are disposed at an angle to each other, wherein said angle is not 180°

.

32. The method as claimed in claim 25, wherein said dielectric comprises air.

33. The method as claimed in claim 25, wherein said waveguide has an incident end and each one of said radiating apertures is spaced at increasing distance from said incident end, and each one of said apertures has an inner width and an outer width, wherein said inner width and outer width of each one of said apertures decrease as the distance of each one of said apertures from the incident end increases.