US4298876A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polarizer for microwave antenna
Assignee: Thales SA
•
Filing: 1980-02-25
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Granted: 1981-11-03
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Expires: 2000-02-25
Abstract
Abstract A reflection-type polarizer for modifying the polarization of an incident electromagnetic wave. The polarizer comprises a reflector positioned at a predetermined distance from a polarization filter constituted by a metal plate having a bi-dimensional periodic network of resonant slots at the operating frequency. The polarizer has application to microwave antenna systems and particularly to Cassegrain antennas.
Inventors
- 👤 Pierre Crochet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:43
CPC Classifications
H; H01; H01Q; H01Q15/00; H01Q15/24; H01Q15/242; H01Q15/246; H01Q15/248; H01Q19/00; H01Q19/10; H01Q19/18; H01Q19/19; H01Q19/195
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
67 words
A polarizer for a microwave antenna operating at a wavelength λ, comprising: a polarization filter; a reflector; and means for rigidly joining said polarization filter and said reflector so that they are spaced at a distance λ/ 4 from one another, the polarization filter including a conductive plate, and a periodic network of resonant slots at the operating frequency of the antenna provided in said conductive plate.
Claim 2
Dependent Claim
67 words
A polarizer for a microwave antenna operating at a wavelength λ, comprising: a polarization filter; a reflector; and means for rigidly joining said polarization filter and said reflector so that they are spaced at a distance λ/ 4 from one another, the polarization filter including a conductive plate, and a periodic network of resonant slots at the operating frequency of the antenna provided in said conductive plate.
Claim 3
Dependent Claim
30 words
A polarizer according to claim 1 wherein said means for rigidly joining comprises a boarder formed on said reflector to which is rigidly attached a portion of said polarizing filter.
Claim 4
Dependent Claim
18 words
A polarizer according to claim 1 wherein said reflector and polarization filter are fabricated from a metallic material.
Claim 5
Dependent Claim
21 words
A polarizer according to claim 1 wherein said polarizing filter and reflector comprise a dielectric panel metallized on both faces thereof.
Claim 6
Dependent Claim
12 words
A polarizer according to claim 1 further comprising a central opening therein.
Claim 7
Dependent Claim
91 words
A microwave antenna, comprising: a radome having a network of parallel wires on a face thereof; a primary source located on an axis of the antenna and within said radome; and a movable polarizer, the polarizer comprising a polarization filter, a reflector, and means for rigidly joining said polarization filter and said reflector so that they are spaced at a distance λ/4 from one another, the polarization filter including a conductive plate, and a periodic network of resonant slots at the operating frequency of the antenna provided in said conductive plate.
Claim 8
Dependent Claim
91 words
A microwave antenna, comprising: a radome having a network of parallel wires on a face thereof; a primary source located on an axis of the antenna and within said radome; and a movable polarizer, the polarizer comprising a polarization filter, a reflector, and means for rigidly joining said polarization filter and said reflector so that they are spaced at a distance λ/4 from one another, the polarization filter including a conductive plate, and a periodic network of resonant slots at the operating frequency of the antenna provided in said conductive plate.
Claim 9
Dependent Claim
31 words
A microwave antenna according to claim 6 wherein said means for rigidly joining comprises a boarder formed on said reflector to which is rigidly attached a portion of said polarizing filter.
Claim 10
Dependent Claim
19 words
A microwave antenna according to claim 6 wherein said reflector and polarization filter are fabricated from a metallic material.
Claim 11
Dependent Claim
22 words
A microwave antenna according to claim 6 wherein said polarizing filter and reflector comprise a dielectric panel metallized on both faces thereof.
Claim 12
Dependent Claim
13 words
A microwave antenna according to claim 6 further comprising a central opening therein.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-11-02 | 1985-05-04 | 1985-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-02 | 1989-05-04 | 1989-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-02 | 1993-05-04 | 1993-11-03 | $7700.00 | Window Closed / Lapsed |