Dual-circular polarized antenna system
In an example embodiment, an azimuth combiner comprises: a septum layer comprising a plurality of septum dividers; first and second housing layers attached to first and second sides of the septum layer; a linear array of ports on a first end of the combiner; wherein the first and second housing layers each comprise waveguide H-plane T-junctions; wherein the waveguide T-junctions can be configured to perform power dividing/combining; and wherein the septum layer evenly bisects each port of the linear array of ports. A stack of such azimuth combiners can form a two dimensional planar array of ports to which can be added a horn aperture layer, and a grid layer, to form a dual-polarized, dual-BFN, dual-band antenna array.
1. A method of manufacturing an antenna array, the method comprising:
forming a plurality of combiner sticks, wherein each of the plurality of combiner sticks comprises a linear array of ports arranged along a first dimension and coupled to a common port via a network of combiner/dividers, and wherein the plurality of combiner sticks are stacked along a second dimension such that the linear array of ports of the plurality of combiner sticks define a two-dimensional grid of ports;
attaching a horn plate comprising an array of horn elements coupled to the plurality of combiner sticks, wherein each horn element of the array of horn elements includes a horn port coupled to a corresponding port of the two-dimensional grid of ports and further includes an aperture port; and
attaching a grid plate coupled to the horn plate, the grid plate dividing the aperture port of each horn element into a corresponding plurality of apertures.
2. The method of claim 1 , further comprising attaching an aperture close out coupled to the grid plate.
3. The method of claim 2 , wherein the attaching the horn plate comprises fixedly attaching the horn plate to the plurality of combiner sticks via a plurality of attachment holes between the two-dimensional grid of ports.
4. The method of claim 1 , wherein forming the plurality of combiner sticks comprises:
individually forming each of the plurality of the combiner sticks; and
stacking each of the plurality of the combiner sticks along the second dimension.
5. The method of claim 4 , wherein the individually forming each of the plurality of the combiner sticks comprises:
forming a plurality of layers;
stacking each of the plurality of layers along the second dimension.
6. The method of claim 5 , wherein:
each of the plurality of layers includes an alignment hole; and
the stacking each of the plurality of layers along the second dimension includes placing an alignment pin in the alignment hole of each of the plurality of layers.
7. The method of claim 5 , wherein:
the forming the plurality of layers comprises:
forming a septum layer;
forming a first combiner/divider layer comprising a portion of a first set of waveguides coupled to the linear array of ports; and
forming a second combiner/divider layer comprising a portion of a second set of waveguides coupled to the linear array of ports; and
the stacking each of the plurality of layers along the second dimension comprises:
stacking the septum layer between the first combiner/divider layer and the second combiner/divider layer.
8. The method of claim 7 , wherein:
forming the first combiner/divider layer comprises removing material from a first side of the first combiner/divider layer; and
forming the second combiner/divider layer comprises removing material from a first side of the second combiner/divider layer.
9. The method of claim 7 , wherein the stacking the septum layer between the first combiner/divider layer and the second combiner/divider layer comprises:
attaching the first side of the first combiner/divider layer to a first side of the septum layer;
attaching the first side of the second combiner/divider layer to a second side of the septum layer.
10. The method of claim 7 , wherein:
forming the first combiner/divider layer further comprises removing material from a second side of the first combiner/divider layer; and
forming the second combiner/divider layer comprises removing material from a second side of the second combiner/divider layer.
11. The method of claim 1 , wherein forming the plurality of combiner sticks comprises:
individually forming each of the plurality of the combiner sticks with material at least partially covering the linear array of ports;
stacking each of the plurality of the combiner sticks along the second dimension; and
machining the plurality of the combiner sticks to remove the material covering the linear array of ports of each of the plurality of the combiner sticks.
12. The method of claim 1 , wherein the common port of each of the plurality of combiner sticks is a first common port associated with a first polarization, the network of combiner/dividers of each of the plurality of combiner sticks is a first network of combiner/dividers, and each of the plurality of combiner sticks further comprises a second common port associated with a second polarization and coupled the linear array of ports via a second network of combiner/dividers.
13. The method of claim 12 , wherein each of the plurality of combiner sticks comprises a plurality of polarizers dividing the linear array of ports into first divided ports and second divided ports, the first divided ports coupled to the first common port via the first network of combiner/dividers, and the second divided ports coupled to the second common port via the second network of combiner/dividers.
14. The method of claim 13 , wherein the plurality of polarizers of each of the plurality of combiner sticks are septum polarizers within a septum layer.
15. The method of claim 1 , wherein the linear array of ports of a first combiner stick of the plurality of combiner sticks are staggered along the first dimension relative to the linear array of ports of a second combiner stick of the plurality of combiner sticks.
16. The method of claim 15 , wherein each of the linear array of ports of the first combiner stick are staggered by the same amount relative to the linear array of ports of the second combiner stick.
17. The method of claim 1 , wherein the grid plate suppresses grating lobes of the antenna array.
18. The method of claim 1 , wherein the linear array of ports of each of the plurality of combiner sticks is a one-by-N array, where N is the number of ports of each of the plurality of combiner sticks.
19. The method of claim 1 , wherein each of the plurality of combiner sticks is a row of the antenna array.
20. The method of claim 1 , wherein each of the plurality of combiner sticks comprises a plurality of layers.
21. The method of claim 20 , wherein:
the common port of each of the plurality of combiner sticks is a first common port associated with a first polarization;
the network of combiner/dividers of each of the plurality of combiner sticks is a first network of combiner/dividers within a first set of layers of the plurality of layers; and
each of the plurality of combiner sticks further comprises a second common port associated with a second polarization and coupled the linear array of ports via a second network of combiner/dividers, the second network of combiner/dividers within a second set of layers of the plurality of layers.
22. The method of claim 21 , wherein the first set of layers is separated from the second set of layers by at least one layer of the plurality of layers.
23. The method of claim 1 , wherein the linear array of ports of a first combiner stick of the plurality of combiner sticks is a first number of ports, and the plurality of combiner sticks of the antenna array is a second number of combiner sticks, the first number greater than the second number.
24. The method of claim 1 , further comprising an elevation combiner network coupled to the common port of each of the plurality of combiner sticks.
25. The method of claim 1 , wherein the common port of each of the plurality of combiner sticks is centrally located relative to the linear array of ports.
26. The method of claim 1 , wherein the linear array of ports of each of the plurality of combiner sticks is on a first side of the antenna array, and the common port of each of the plurality of combiner sticks is on a second side of the antenna array.
27. The method of claim 26 , wherein the second side of the antenna array is opposite the first side of the antenna array.
28. The method of claim 1 , wherein the plurality of combiner sticks, the horn plate and the grid plate define an antenna aperture, and further comprising attaching a positioner coupled to the antenna aperture.
29. The method of claim 28 , wherein the positioner is a mechanical antenna pointing system.
30. The method of claim 1 , wherein each of the plurality of combiner sticks has a thickness in the second dimension that is less than or equal to one wavelength at a highest operating frequency of the antenna array.