Wide bandwidth hybrid mode feeds
First Claim
1. A hybrid mode feed arrangement comprising:
- a smooth-walled feedhorn comprising a hollow conductive waveguide section (10) for propagating the TE11 mode introduced at an entrance of the feedhorn and an outwardly flared conductive end section (11) at an aperture of the feedhorn, both the hollow waveguide and flared end sections including an inner (15) and an outer longitudinal wall surface; and
a rod (12) of dielectric material comprising a first end section including an outer wall which symmetrically engages a longitudinal portion (14) of the inner surface of the hollow waveguide section for intercepting the TE11 mode propagating in said hollow waveguide section and further extends through the flared end section and beyond the aperture of the feedhorn in a non-contacting arrangement for converting the TE11 mode into the HE11 mode and propagating the HE11 mode therein, and a second end section protruding beyond the aperture of the feedhorn comprising an outwardly tapered horn (30) including a curved aperture at the wide end thereof for launching the HE11 mode.
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Accused Products
Abstract
The present invention relates to hybrid mode feeds which are capable of handling very wide bandwidths. In the present feed arrangements, a dominant TE11 mode is converted to the HE11 hybrid mode which is then launched. The TE11 to HE11 mode conversion is achieved by inserting a circular dielectric rod (12) into a flared end (11) of a smooth-walled cylindrical feedhorn until a small cylindrical section of the dielectric rod engages with the inner wall (15) of the unflared portion of the feedhorn. In one feed arrangement, the other end of the dielectric rod is similarly inserted into a flared end (21) of a corrugated cylindrical feedhorn section (22) until a short longitudinal section of the cylindrical portion of the rod is concentric with the corrugations of an unflared section of the feedhorn to provide a transition for the HE11 mode into the corrugated waveguide for subsequent launch. In a second feed arrangement, the dielectric rod at the aperture of the smooth-walled flared feedhorn is flared outward to end in a curved configuration which is shaped to minimize reflections back into the dielectric rod and provide a predetermined wavefront at the aperture of the feed.
162 Citations
7 Claims
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1. A hybrid mode feed arrangement comprising:
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a smooth-walled feedhorn comprising a hollow conductive waveguide section (10) for propagating the TE11 mode introduced at an entrance of the feedhorn and an outwardly flared conductive end section (11) at an aperture of the feedhorn, both the hollow waveguide and flared end sections including an inner (15) and an outer longitudinal wall surface; and a rod (12) of dielectric material comprising a first end section including an outer wall which symmetrically engages a longitudinal portion (14) of the inner surface of the hollow waveguide section for intercepting the TE11 mode propagating in said hollow waveguide section and further extends through the flared end section and beyond the aperture of the feedhorn in a non-contacting arrangement for converting the TE11 mode into the HE11 mode and propagating the HE11 mode therein, and a second end section protruding beyond the aperture of the feedhorn comprising an outwardly tapered horn (30) including a curved aperture at the wide end thereof for launching the HE11 mode. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification