Dual-polarization rippled reflector antenna
An antenna may include a reflector and a multi-band feed assembly. A support member may be coupled to the multi-band feed assembly to orient the multi-band feed assembly for direct illumination of the reflector. The multi-band feed assembly may include first and second feeds, each having a respective septum polarizer coupled between a respective common waveguide and a respective pair of waveguides. A housing of the support member may contain the respective septum polarizers and the respective pairs of waveguides.
1. An antenna comprising:
a single reflector having a shaped surface, wherein the shaped surface comprises a plurality of ripples extending from a center of the single reflector to a first distance from the center, and wherein maximum deviations of respective ripples of the plurality of ripples from a parabolic surface between the center and an edge of the single reflector reduce with increased distance of the respective ripples from the center; and
a feed illuminated by the single reflector, the feed comprising a polarizer coupled between a common waveguide and a first waveguide and a second waveguide of a pair of waveguides.
2. The antenna of claim 1 , wherein the center has a deviation from the parabolic surface.
3. The antenna of claim 1 , wherein the plurality of ripples is a first plurality of ripples and the shaped surface comprises a second plurality of ripples extending from the first distance to the edge of the single reflector.
4. The antenna of claim 3 , wherein the first plurality of ripples comprise respective first portions and respective second portions that are on opposing sides of the parabolic surface.
5. The antenna of claim 4 , wherein the second plurality of ripples are located exclusively on a single side of the parabolic surface.
6. The antenna of claim 1 , wherein the center has a deviation from the parabolic surface.
7. The antenna of claim 1 , wherein the edge has a deviation from the parabolic surface.
8. The antenna of claim 1 , wherein the shaped surface is a continuous surface between the center and the edge of the single reflector.
9. The antenna of claim 1 , wherein a profile of the shaped surface is symmetrical about a central axis of the single reflector.
10. The antenna of claim 1 , wherein the shaped surface has a first profile between the center and a first location at the edge of the single reflector and a second profile of the shaped between the center and a second location at the edge of the single reflector, the second profile different than the first profile.
11. The antenna of claim 10 , wherein the plurality of ripples is a first plurality of ripples comprising the first profile and the second profile comprises a second plurality of ripples, and wherein the first plurality of ripples has a first deviation from the parabolic surface at a particular distance from the center, and the second plurality of ripples has a second deviation from the parabolic surface at the particular distance that is different than the first deviation.
12. The antenna of claim 1 , wherein the center is a location on the shaped surface at which a boresight of the feed is oriented.
13. The antenna of claim 1 , further comprising:
a support member to orient the feed for direct illumination of the shaped surface of the single reflector.
14. The antenna of claim 13 , wherein the support member extends through an opening of the single reflector.
15. The antenna of claim 14 , wherein the opening is at a periphery of the single reflector.
16. The antenna of claim 13 , wherein the support member has an arcuate shape.
17. The antenna of claim 16 wherein the support member has a leading edge along the arcuate shape that is oriented towards the single reflector and has a tapered cross-section.
18. The antenna of claim 17 , wherein the tapered cross-section is beveled.
19. The antenna of claim 17 , wherein the tapered cross-section mitigates scattering interaction between the support member and the single reflector.
20. The antenna of claim 17 , wherein the support member has a trailing edge oriented away from the single reflector having a different cross-section than the leading edge.
21. The antenna of claim 20 , wherein the trailing edge has a flat cross-section.
22. The antenna of claim 20 , wherein the support member is within a swept volume of the single reflector.
23. The antenna of claim 1 , wherein the edge of the single reflector is non-circular.
24. The antenna of claim 1 , wherein the polarizer is a septum polarizer.