Patent US3680138A successfully refreshed from Google Patents.
US3680138A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cross-mode reflector for the front element of an array antenna
Assignee: United States Department of the Army
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Filing: 1970-09-21
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Granted: 1972-07-25
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Expires: 1990-09-21
Abstract
Abstract A circular aperture waveguide emitting element of cross-section comparable with the emitted wavelengths is made to have a linear polarization output by a cross-mode reflector which is a resonant bar mounted on a window located in the aperture.
Inventors
- 👤 Harold A Wheeler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:36
CPC Classifications
H; H01; H01Q; H01Q13/00; H01Q13/06; H01Q15/00; H01Q15/24
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
42 words
A radiation waveguide emitting element having a circular waveguide cavity and circular aperture with dimensions in all directions comparable with the wavelength of emitted radiation; and a reflecting bar located in the aperture so as to short circuit any cross-mode radiation emissions.
Claim 2
Dependent Claim
42 words
A radiation waveguide emitting element having a circular waveguide cavity and circular aperture with dimensions in all directions comparable with the wavelength of emitted radiation; and a reflecting bar located in the aperture so as to short circuit any cross-mode radiation emissions.
Claim 3
Dependent Claim
34 words
A radiation emitting element as set forth in claim 1, wherein a dielectric window is secured in said aperture and said reflecting bar is elongated and secured to one surface of said dielectric window.
Claim 4
Dependent Claim
27 words
An element as set forth in claim 2, wherein said reflecting bar has its corners rounded, and its ends are spherical and bent away from the aperture.
Claim 5
Dependent Claim
80 words
An element as set forth in claim 3, wherein the circular waveguide is a shell of two sections having different diameters; a dielectric window brazed to the shell so as to be located in the aperture; a full-wave radiating loop; a coaxial connector connected through said shell to the full-wave radiating loop; and said reflecting bar being a cross-mode reflector which is brazed to the dielectric window inside the shell and at a right angle to the full-wave radiating loop.
Claim 6
Dependent Claim
30 words
An element as set forth in claim 2 wherein a plurality of such elements make up front elements of a phased-array radar; and the radiation emitted therefrom is linear polarized.
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |