Dual band feed window

1. A feed window for a feed assembly having at least one primary feed operating at a primary frequency band and at least one secondary feed operating at a secondary frequency band, the feed window comprising:

a feed window sealing against the feed assembly, enclosing an open end of the primary feed(s) and the secondary feed(s);

the feed window having a feed window surface supported by and spaced away from the feed assembly by a feed window wall;

the feed window surface of the feed window generally parallel to a launch edge of the primary feed(s) and the secondary feed(s);

an inner window insert positioned between the feed window surface and the primary feed and the secondary feed;

the inner window insert having an inner window insert surface generally parallel to the feed window surface.

2. The assembly of claim 1 , wherein the inner window insert surface is positioned a distance from the feed window surface corresponding to a multiple of one of a mid-band operating frequency wavelength of the primary frequency band and a mid-band operating frequency wavelength of the secondary frequency band.

3. The assembly of claim 2 , wherein the multiple is one eighth wavelength.

4. The assembly of claim 1 , wherein the launch edge(s) of one of the primary feed and the secondary feed are spaced away from the feed window surface, by a distance corresponding to a multiple of one of a mid-band operating frequency wavelength of the primary frequency band and a second multiple of a mid-band operating frequency wavelength of the secondary frequency band.

5. The assembly of claim 2 , wherein the multiple is one quarter wavelength.

6. The assembly of claim 1 , wherein the inner window insert has an insert aperture(s) corresponding to a feed view window of one of the primary feed(s) and the secondary feed(s).

7. The assembly of claim 1 , wherein the insert is seated against a shoulder formed in the feed window wall.

8. The assembly of claim 1 , further including a plurality of retaining tabs formed in the feed window wall; the retaining tabs operating to retain the feed window against the feed assembly.

9. The assembly of claim 1 , wherein the primary frequency band is Ka band and the secondary frequency band is Ku band.

10. The assembly of claim 1 , wherein the feed window and the inner window insert are each formed by injection molding of a dielectric material.

11. The assembly of claim 1 , wherein the feed window surface and the inner window insert surface is flat.

12. The assembly of claim 1 , wherein the feed window surface is curved.

13. The assembly of claim 1 , wherein the inner window insert surface in the field of view of the primary feed is positioned a distance from the feed window surface corresponding to a multiple of a mid-band operating frequency wavelength of the primary frequency band; and

the insert surface in the field of view of the secondary feed is positioned a distance from the feed window surface corresponding to a multiple of a mid-band operating frequency wavelength of the secondary frequency band;

the areas of the insert surface at different distances from the feed window surface separated from one another by a step in the inner window insert surface.

14. A feed window for a feed assembly having at least one primary feed operating at a primary frequency band and at least one secondary feed operating at a secondary frequency band, the feed window comprising:

a feed window sealing against the feed assembly, enclosing an open end of the primary feed(s) and the secondary feed(s);

the feed window having a feed window surface supported by and spaced away from the feed assembly by a feed window wall;

the feed window surface of the feed window generally parallel to a launch edge of the primary feed(s) and the secondary feed(s); and

an inner window insert seated against a shoulder formed in the feed window wall, positioned between the feed window surface and both of the primary feed and the secondary feed;

the inner window insert having an inner window insert surface generally parallel to the feed window surface;

the inner window insert having an insert aperture(s) corresponding to a feed view window of one of the primary feed(s) and the secondary feed(s).