Integrated waveguide antenna and array
An antenna is provided. The antenna may include at least one open-ended structure extending from a surface of a waveguide. The open-ended structure may have a cross section of many different shapes. The walls of the structure may be movable. The antenna structure may be rotated. The antenna may incorporate a number of different wave feeds. The antenna may provide two-dimensional beam steering.
1. An antenna comprising:
a parallel plate waveguide having a top plate, a bottom plate, and a backside,
at least one radiating element extending from the top plate of the waveguide over an aperture formed in the top plate, the element comprising a sidewall forming a distal opening spaced apart from the top plate of the waveguide, and wherein the center of the aperture is formed at a distance L from the backside, the distance L selected so that a reflecting wave reflected from the backside returns in phase with a propagating wave that is propagating towards the backside.
2. The antenna of claim 1 , wherein the at least one radiating element comprises an extruded portion having a proximal end and a distal end, and further comprising at least one wall portion extending from the proximal end to the distal end, and wherein the extruded portion forms a tube having openings at the proximal end and the distal end.
3. The antenna of claim 1 , wherein the at least one radiating element has a polygonal cross section.
4. The antenna of claim 1 , wherein the at least one radiating element has a curved cross section.
5. The antenna of claim 1 , wherein the at least one radiating element has a trapezoidal cross section.
6. The antenna of claim 1 , wherein the at least one radiating element has a square cross section.
7. The antenna of claim 1 , wherein the at least one radiating element has a rectangular cross section.
8. The antenna of claim 1 , wherein the at least one radiating element has a cross-shaped cross section.
9. The antenna of claim 1 , wherein the at least one radiating element has a cross-shaped cross section with tapered rectangular ridges.
10. The antenna of claim 1 , wherein the at least one radiating element is tubular.
11. The antenna of claim 1 , wherein the at least one radiating element is cylindrical.
12. The antenna of claim 1 , wherein the at least one radiating element is conical.
13. The antenna of claim 1 , wherein the at least one element has a first portion and a second portion, the first portion comprising at least one wall perpendicular to the surface of the waveguide, the second portion comprising at least one wall non-perpendicular to the surface of the waveguide.
14. The antenna of claim 1 , wherein the at least one radiating element comprises a perpendicular portion and a flared portion.
15. The antenna of claim 1 , wherein the waveguide comprises at least one end opening and wherein the waveguide is adapted to receive an excitation wave at least one of the end openings.
16. The antenna of claim 1 , further comprising a wave source.
17. The antenna of claim 1 , wherein the side wall of the radiating element forms a cylindrical cross section and further comprises at least two slots formed therein.
18. The antenna of claim 16 , wherein the side wall of the radiating element comprises a conical shape.
19. The antenna of claim 1 , wherein the waveguide comprises a polygon cross section.
20. The antenna of claim 1 wherein the waveguide comprises a circular cross section.
21. The antenna of claim 1 , wherein the sidewall extends so as to place the distal opening at a height of a quarter wavelength (0.25λ) above the top plate.
22. The antenna of claim 1 , wherein the sidewall is formed so that each distal opening has an area larger than area of the corresponding aperture.