Compact feed system with developable waveguide H-plane directional coupler
A compact feed system ( 600 ) is provided which comprises an orthomode transducer or junction ( 400 ) and a waveguide H-plane directional coupler ( 100 ). The waveguide H-plane directional coupler may comprise two hollow waveguide sections ( 110, 120 ) and a coupling section ( 130 ) arranged in between the two hollow waveguide sections for coupling a signal from one hollow waveguide section to another hollow waveguide section. In a transverse cross-section of the waveguide H-plane directional coupler, the hollow waveguide sections may be angled towards the coupling section and delimit a recess ( 20 ) formed at an inner side of the waveguide H-plane directional coupler. The orthomode transducer or junction ( 400 ) may be positioned at least partially in the recess to increase compactness of the feed system.
1 . A compact feed system comprising:
an orthomode transducer or junction;
a waveguide H-plane directional coupler comprising:
two hollow waveguide sections each providing a respective transmission line in a longitudinal direction of the waveguide H-plane directional coupler;
a coupling section arranged in between the two hollow waveguide sections for coupling a signal from one hollow waveguide section to another hollow waveguide section;
wherein, in a transverse cross-section of the waveguide H-plane directional coupler, the hollow waveguide sections are angled towards the coupling section and delimit a recess formed at an inner side of the waveguide H-plane directional coupler; and
wherein the orthomode transducer or junction is positioned at least partially in the recess.
2 . The feed system according to claim 1 , wherein the hollow waveguide sections and the coupling section are shaped so that an H-plane of the waveguide H-plane directional coupler conforms to a developable surface.
3 . The feed system according to claim 2 , wherein the developable surface corresponds to a surface part of a cylinder or parallelepiped or hexagonal prism.
4 . The feed system according to claim 1 , wherein the hollow waveguide sections are curved towards each other in the transverse cross-section of the waveguide H-plane directional coupler.
5 . The feed system according to claim 4 , wherein the coupling section is curved in the transverse cross-section of the waveguide H-plane directional coupler and has a curvature which follows that of the two hollow waveguide sections.
6 . The feed system according to claim 1 , wherein at least one of the two hollow waveguide sections has a chamfer or radius on an edge in the transverse cross-section of the waveguide H-plane directional coupler, which edge is nearest to the other hollow waveguide section.
7 . The feed system according to claim 6 , wherein the chamfer or radius is on one or more edges nearest to the coupling section.
8 . The feed system according to claim 1 , further comprising a filter for coupling the orthomode transducer or junction to the waveguide H-plane directional coupler.
9 . The feed system according to claim 8 , wherein the filter comprises at least a stub and an iris, wherein the stub is arranged within a convex envelop of the waveguide H-plane directional coupler, the orthomode transducer or junction, and the iris.
10 . An arrangement of a plurality of feed systems each according to claim 1 , wherein the feed systems are arranged longitudinally in parallel and transversally in accordance with a lattice.
11 . The arrangement according to claim 10 , wherein the arrangement of the plurality of feed systems is manufactured as a multi-layer assembly using for example an additive manufacturing technique or CNC milling.