US4241353A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multimode monopulse feed and antenna incorporating same
Assignee: Thales SA
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Filing: 1979-02-21
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Granted: 1980-12-23
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Expires: 1999-02-21
Abstract
Abstract A mixed E-plane and H-plane multimode monopulse feed is formed by a multimode E-plane horn structure, in the aperture of which metal bars or plates are arranged parallel to the electrical field. The bars or plates form discontinuities at which an odd mode of the H 30 type is generated, the feed as a whole thus becoming a multimode H-plane structure. Such a feed is very useful for the production of multimode monopulse antennas of reduced dimensions.
Inventors
- 👤 Francois Salvat
- 👤 Jean Bouko
- 👤 Claude Coquio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:17
CPC Classifications
H; H01; H01Q; H01Q25/00; H01Q25/04; H01Q19/00; H01Q19/06; H01Q19/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
136 words
A multimode monopulse feed comprising an E-plane multimode structure producing the E function, an H-plane multimode structure producing the H function, the aperture of the H-plane structure forming the aperture of the multimode microwave feed, a group of waveguides connected to the input of said E-plane structure, which waveguides are excited in the fundamental mode, said E-plane multimode structure terminating in a flared horn presenting an aperture, at least two obstacles being placed in said aperture in such a way that said obstacles have a longitudinal dimension parallel to the electric field in said aperture, said obstacles generating an odd propagative upper mode of the H 30 type, the said multimode structure forming a mixed E-plane and H-plane structure of reduced length in whose aperture the E-plane and H-plane illumination characteristics are controllable independently but simultaneously.
Claim 2
Dependent Claim
136 words
A multimode monopulse feed comprising an E-plane multimode structure producing the E function, an H-plane multimode structure producing the H function, the aperture of the H-plane structure forming the aperture of the multimode microwave feed, a group of waveguides connected to the input of said E-plane structure, which waveguides are excited in the fundamental mode, said E-plane multimode structure terminating in a flared horn presenting an aperture, at least two obstacles being placed in said aperture in such a way that said obstacles have a longitudinal dimension parallel to the electric field in said aperture, said obstacles generating an odd propagative upper mode of the H 30 type, the said multimode structure forming a mixed E-plane and H-plane structure of reduced length in whose aperture the E-plane and H-plane illumination characteristics are controllable independently but simultaneously.
Claim 3
Dependent Claim
19 words
A multimode monopulse feed according to claim 1, having a longitudinal dimension corresponding to that of said E-plane structure.
Claim 4
Dependent Claim
40 words
A multimode monopulse feed according to claim 1 wherein the odd upper mode of the H 30 type is generated in the very aperture of the feed, the in-phase relationship being constant whatever the frequency, resulting in an increased passband.
Claim 5
Dependent Claim
17 words
A multimode monopulse feed according to claim 3 wherein the passband is of the order of 15%.
Claim 6
Dependent Claim
56 words
A multimode monopulse feed according to claim 1 wherein the obstacles inserted in the aperture of the feed parallel to the electrical field of the emitted wave are bars arranged symmetrically about the axis of the aperture and separated by a distance c less than the length a of the aperture and such that O<(a -c)<a/3.
Claim 7
Dependent Claim
32 words
A multimode monopulse feed according to claim 5 wherein a second pair of bars situated in said aperture a quarter wavelength upstream of the first pair is provided for matching the feed.
Claim 8
Dependent Claim
30 words
A multimode monopulse feed according to claim 1 wherein the obstacles inserted in the aperture of the feed are plates having a width of the order of a quarter wavelength
Claim 9
Dependent Claim
35 words
A multimode monopulse feed according to claim 1 wherein the aperture of the structure is pyramidal and produces a square phase law which stabilizes the angular width of the radiation patterns in the H plane.
Claim 10
Dependent Claim
21 words
A multimode monopulse feed according to claim 1 wherein the phase centers in the E plane and the H plane coincide.
References Cited (Backward Citations)
US3701163A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |