Patent US4077039A successfully refreshed from Google Patents.
US4077039A
Expired / Lapsed
US
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Launching and/or receiving network for an antenna feedhorn
Assignee: AT&T Inc
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Filing: 1976-12-20
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Granted: 1978-02-28
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Expires: 1996-12-20
Abstract
Abstract A launching and/or receiving network is disclosed capable of coupling radio signals in a first frequency band, e.g., 2 GHz into and/or out of an existing antenna system without perturbing the signals being transmitted in other frequency bands, e.g., 4, 6 and/or 11 GHz. The first frequency band signal is launched through an evanescent mode waveguide filter which is both coupled to the flared sidewall of a feedhorn through an H-plane, T-junction, and provides a very broad stopband for the signals in the other frequency bands being launched in the feedhorn. To minimize mode conversion for the signals in the other frequency bands, a dummy evanescent mode waveguide filter is connected at one end thereof to the feedhorn facing the first frequency band launching network and at the other end thereof to a matched load through a waveguide section. A second launching and/or receiving network can be similarly coupled to the feedhorn in a plane normal to the first network to permit a different orthogonally polarized beam, at the first frequency band, to be simultaneously transmitted and/or received by each of the two networks.
Inventors
- 👤 Chung-Li Ren
- 👤 Han-Chiu Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:09
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/20; H01P1/213; H01P1/2131; H01Q; H01Q5/00; H01Q5/40; H01Q5/45
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
176 words
A network for an antenna for either launching or receiving signals in a first frequency band, the antenna comprising a flared feedhorn and a waveguide transmission line which will support signals in a second frequency band, the network comprising: a first evanescent mode waveguide filter coupled at a first end thereof to a first sidewall of the flared portion of the feedhorn through an H-plane, T-junction and at a second end thereof to a waveguide section capable of propagating signals at the first frequency band, said first waveguide filter being dimensioned and tunable to pass the first frequency band signals and to have a very broad stopband for the second frequency band signals; and a second evanescent mode waveguide filter coupled at a first end thereof to a second sidewall of the flared portion of the feedhorn through an H-plane, T-junction at a location directly opposite and facing said first waveguide filter and at a second end thereof to a load termination, said second waveguide filter having the same filter characteristics as said first waveguide filter.
Claim 2
Dependent Claim
176 words
A network for an antenna for either launching or receiving signals in a first frequency band, the antenna comprising a flared feedhorn and a waveguide transmission line which will support signals in a second frequency band, the network comprising: a first evanescent mode waveguide filter coupled at a first end thereof to a first sidewall of the flared portion of the feedhorn through an H-plane, T-junction and at a second end thereof to a waveguide section capable of propagating signals at the first frequency band, said first waveguide filter being dimensioned and tunable to pass the first frequency band signals and to have a very broad stopband for the second frequency band signals; and a second evanescent mode waveguide filter coupled at a first end thereof to a second sidewall of the flared portion of the feedhorn through an H-plane, T-junction at a location directly opposite and facing said first waveguide filter and at a second end thereof to a load termination, said second waveguide filter having the same filter characteristics as said first waveguide filter.
Claim 3
Dependent Claim
33 words
A network according to claim 1 wherein the first and second evanescent mode waveguide filters are each coupled to the feedhorn through an I-shaped opening formed from a central inwardly-extending bisected capacitive post.
Claim 4
Dependent Claim
44 words
A network according to claim 2 wherein at least one of the halves of the bisected capacitive post includes a threaded aperture for mounting a tuning screw for the fine tuning of a desired center frequency in the first frequency band at the opening.
Claim 5
Dependent Claim
31 words
A network according to claim 2 wherein said bisected capacitive post forms the capacitive waveguide element in the section of the first and second evanescent mode waveguide filters nearest said feedhorn.
Claim 6
Dependent Claim
48 words
A network according to claim 1 wherein the waveguide section coupled to the second end of said first evanescent mode waveguide filter has a height dimension which substantially corresponds to the height dimension for said first evanescent mode waveguide filter to intensify the field within said waveguide section.
Claim 7
Dependent Claim
350 words
Apparatus for an antenna for either launching or receiving two orthogonally polarized signals in a first frequency band, the antenna comprising a flared feedhorn and a waveguide transmission line which will support signals in a second frequency band, the apparatus comprising: a first network oriented to either launch or receive a first one of the two orthogonally polarized signals comprising a first evanescent mode waveguide filter coupled at a first end thereof to a first sidewall of the flared portion of the feedhorn through a T-junction and at a second end thereof to a waveguide section capable of propagating signals at the first frequency band, said first waveguide filter being dimensioned and tunable to pass the first frequency band signals and to have a very broad stopband for the second frequency band signals, and a second evanescent mode waveguide filter coupled at a first end thereof to a second sidewall of the flared portion of the feedhorn through a T-junction at a location directly opposite and facing said first waveguide filter and at a second end thereof to a load termination, said second waveguide filter having the same filter characteristics as said first waveguide filter; and a second network oriented to either launch or receive a second one of the two orthogonally polarized signals comprising a first evanescent mode waveguide filter coupled at a first end thereof to a third sidewall of the flared portion of the feedhorn through a T-junction and at a second end thereof to a waveguide section capable of propagating signals at the first frequency band, said first waveguide filter being dimensioned and tunable to pass the first frequency band signals and to have a very broad stopband for the second frequency band signals, and a second evanescent mode waveguide filter coupled at a first end thereof to a fourth sidewall of the flared portion of the feedhorn through a T-junction at a location directly opposite and facing said first waveguide filter and at a second end thereof to a load termination, said second waveguide filter having the same filter characteristics as said first waveguide filter.
Claim 8
Dependent Claim
350 words
Apparatus for an antenna for either launching or receiving two orthogonally polarized signals in a first frequency band, the antenna comprising a flared feedhorn and a waveguide transmission line which will support signals in a second frequency band, the apparatus comprising: a first network oriented to either launch or receive a first one of the two orthogonally polarized signals comprising a first evanescent mode waveguide filter coupled at a first end thereof to a first sidewall of the flared portion of the feedhorn through a T-junction and at a second end thereof to a waveguide section capable of propagating signals at the first frequency band, said first waveguide filter being dimensioned and tunable to pass the first frequency band signals and to have a very broad stopband for the second frequency band signals, and a second evanescent mode waveguide filter coupled at a first end thereof to a second sidewall of the flared portion of the feedhorn through a T-junction at a location directly opposite and facing said first waveguide filter and at a second end thereof to a load termination, said second waveguide filter having the same filter characteristics as said first waveguide filter; and a second network oriented to either launch or receive a second one of the two orthogonally polarized signals comprising a first evanescent mode waveguide filter coupled at a first end thereof to a third sidewall of the flared portion of the feedhorn through a T-junction and at a second end thereof to a waveguide section capable of propagating signals at the first frequency band, said first waveguide filter being dimensioned and tunable to pass the first frequency band signals and to have a very broad stopband for the second frequency band signals, and a second evanescent mode waveguide filter coupled at a first end thereof to a fourth sidewall of the flared portion of the feedhorn through a T-junction at a location directly opposite and facing said first waveguide filter and at a second end thereof to a load termination, said second waveguide filter having the same filter characteristics as said first waveguide filter.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-27 | 1981-08-29 | 1982-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-27 | 1985-08-29 | 1986-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-27 | 1989-08-29 | 1990-02-28 | $7700.00 | Window Closed / Lapsed |