US3683394A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Clutter fence for suppression of electromagnetic energy
Assignee: AT&T Inc
•
Filing: 1970-07-09
•
Granted: 1972-08-08
•
Expires: 1990-07-09
Abstract
Abstract A conducting or absorbing ground clutter fence at least partly encircles an antenna to block electromagnetic energy in a horizontal band having a vertical height equal to one-half the diameter of the first Fresnel zone of the antenna and, furthermore, having a vertical portion thereof completely within the first Fresnel zone.
Inventors
- 👤 Phillip Hagar Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:39
CPC Classifications
H; H01; H01Q; H01Q17/00; H01Q17/001
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
92 words
A clutter fence for an antenna which fence reduces clutter energy from ground objects, said fence comprising, an elongated sheet-like member formed of material opaque to electromagnetic energy and positioned to at least partly encircle said antenna at a radius R with respect to the effective center of reception of said antenna, said member having one of the longer edges thereof lying substantially in a horizontal plane passing through said center and having a vertical dimension substantially equal to square root R lambda where lambda is the wavelength of the unwanted energy.
Claim 2
Dependent Claim
92 words
A clutter fence for an antenna which fence reduces clutter energy from ground objects, said fence comprising, an elongated sheet-like member formed of material opaque to electromagnetic energy and positioned to at least partly encircle said antenna at a radius R with respect to the effective center of reception of said antenna, said member having one of the longer edges thereof lying substantially in a horizontal plane passing through said center and having a vertical dimension substantially equal to square root R lambda where lambda is the wavelength of the unwanted energy.
Claim 3
Dependent Claim
15 words
A fence in accordance with claim 1 in which said material absorbs energy impinging thereon.
Claim 4
Dependent Claim
15 words
A fence in accordance with claim 1 in which said material reflects energy impinging thereon.
Claim 5
Dependent Claim
95 words
A clutter fence for an antenna which fence comprises, an elongated sheet-like member formed of material opaque to electromagnetic energy, and supporting means at least partly encircling said antenna and having said member attached thereto to position said member at a radius R with respect to the effective center of said antenna with one longer edge of said member lying substantially in a horizontal plane passing through said center, said member, when so attached, having a vertical dimension substantially equal to Square Root R lambda , where lambda substantially equals the wavelength of clutter energy.
Claim 6
Dependent Claim
95 words
A clutter fence for an antenna which fence comprises, an elongated sheet-like member formed of material opaque to electromagnetic energy, and supporting means at least partly encircling said antenna and having said member attached thereto to position said member at a radius R with respect to the effective center of said antenna with one longer edge of said member lying substantially in a horizontal plane passing through said center, said member, when so attached, having a vertical dimension substantially equal to Square Root R lambda , where lambda substantially equals the wavelength of clutter energy.
Claim 7
Dependent Claim
15 words
A fence in accordance with claim 4 in which said material absorbs energy impinging thereon.
Claim 8
Dependent Claim
15 words
A fence in accordance with claim 4 in which said material reflects energy impinging thereon.
References Cited (Backward Citations)
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US3495265A
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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) | 1975-08-08 | 1976-02-07 | 1976-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-08 | 1980-02-07 | 1980-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-08 | 1984-02-07 | 1984-08-08 | $7700.00 | Window Closed / Lapsed |