Tulip antenna with tuning stub

• US 20100019979A1
• Filed: 07/25/2008
• Published: 01/28/2010
• Est. Priority Date: 07/25/2008
• Status: Active Grant

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: United States of America As Represented By The Attorney General
• Inventors: Sharp, Brian David, Buxton, Carey Gwynne
• Granted Patent: US 7,791,554 B2
• Time in Patent Office: Days
• US Class Current: 343/722
• CPC Class Codes: H01Q 9/28 Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines waveguide horns or mouths H01Q13/00; slot antennas H01Q13/00

Abstract

The tulip antenna has two orthogonally intersecting conductive plates. Each intersecting plate has two ends, and one of these ends is smoothly tapered. The intersecting plates intersect such that the tapered end of both plates together form a tapered side when the intersecting plates intersect. An inner conductor of a coaxial cable is connected to the two intersecting plates at the tapered side of the intersecting plates. The inner conductor and the surrounding insulator pass through a tuning stub and then through a metallic ground plate. The tuning stub is connected to the ground plate. An aperture in the ground plate is sized such that the insulator can pass through it, just as the insulator can pass through the tuning stub. The tuning stub increases the upper frequency limit over which the antenna operates. The outer conductor of the coaxial cable is attached to the ground plate.

Claims

1. An antenna apparatus, comprising:

a ground plane having a ground plane top surface, a ground plane bottom surface, and a ground plane aperture;

a tuning stub located on the ground plane top surface and having a tuning stub aperture;

a first conductor that is insulated from both the ground plane and the tuning stub and that passes through both the ground plane aperture and the tuning stub aperture;

a first planar radiating element; and

a second planar radiating element, being constructed and arranged to intersect the first planar radiating element;

wherein the first planar radiating element and second planar radiating element attach to the first conductor.

2. The apparatus of claim 1, wherein the first planar radiating element has a curved end, and wherein the second planar radiating element has a curved end.

3. The apparatus of claim 2, wherein the curved end of the first planar radiating element is elliptical and the curved end of the second planar radiating element is elliptical.

4. The apparatus of claim 2, wherein the curved end of the first planar radiating element is circular and the curved end of the second planar radiating element is circular.

5. The apparatus of claim 1, wherein the second planar radiating element is constructed and arranged to intersect the first radiating element orthogonally.

6. The apparatus of claim 1, wherein the first planar radiating element and the second planar radiating element attach to the first conductor at the intersection of the first planar radiating element and the second planar radiating element.

7. The apparatus of claim 1, wherein the conductor is orthogonal to both the ground plane and the tuning stub.

8. The apparatus of claim 1, further comprising a second conductor, wherein the second conductor is insulated from the first conductor and connected to the ground plane.

9. An antenna comprising:

a ground plate having a ground plate aperture;

a coaxial connector that is connected to the ground plate so that an inner conductor of the coaxial connector and a surrounding insulator pass through the ground plate aperture;

a tuning stub on the ground plate having a tuning stub thickness, a tuning stub diameter, and a tuning stub aperture such that the inner conductor of the coaxial connector and surrounding insulator pass through the tuning stub aperture, wherein the tuning stub thickness and the tuning stub diameter will affect the high frequency response of the antenna;

a first conductive sheet having a first tapered end, a first blunt end, a first slot, and a first cutout for receiving the inner conductor of the coaxial connector, wherein the first cutout is located in the center of the first tapered end; and

a second conductive sheet having a second tapered end, a second blunt end, a second slot, and a second cutout for receiving the inner conductor of the coaxial connector, wherein the second cutout is located in the center of the second tapered end.

10. The antenna of claim 9, wherein the ground plate is circular and the ground plate aperture is located in the center of the ground plate.

11. The antenna of claim 9, wherein the inner conductor of the coaxial connector extends perpendicularly from the ground plate.

12. The antenna of claim 9, wherein the first tapered end is elliptically tapered and the second tapered end is elliptically tapered.

13. The antenna of claim 9, wherein the first tapered end is circularly tapered and the second tapered end is circularly tapered.

14. The antenna of claim 9, wherein the first slot and the second slot are constructed and arranged so that the first conductive sheet and the second conductive sheet will intersect such that the first conductive sheet and the second conductive sheet are perpendicular to each other.

15. The antenna of claim 9, wherein the first cutout and the second cutout are constructed and arranged such that when the first conductive sheet and the second conductive sheet intersect, the inner conductor can fit inside the first cutout and the second cutout and the inner conductor is situated in the center of the line formed by the intersection of the first conductive sheet and the second conductive sheet.

16. A method for tuning an antenna comprising:

placing a circular tuning stub, having a thickness, and a diameter, in electrical contact with a ground plane of an antenna having two orthogonally intersecting radiating elements elevated above the ground plane and orthogonal to the ground plane;

adjusting the thickness of the tuning stub to improve the high frequency response of the antenna; and

adjusting the diameter of the tuning stub to improve the high frequency response of the antenna.

17. The method of claim 16, wherein the thickness of the tuning stub is adjusted to 0.056 inches.

18. The method of claim 16, wherein the diameter of the tuning stub is 0.191 inches.

19. The method of claim 17, further comprising adjusting the height of an insulator passing through the tuning stub such that the insulator extends a height of 0.043″

above the thickness of the tuning stub.