US5245352A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Threshold sensitive low visibility reflecting surface
Assignee: Boeing Co
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Filing: 1982-09-30
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Granted: 1993-09-14
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Expires: 2002-09-30
Abstract
Abstract A non-linear solid state conductor placed across a resonant aperture formed in a surface reflective of electromagnetic energy becomes conductive under the influence of a microwave field above a threshhold energy level of intensity to render the resonant aperture fully reflecting for the bandwidth of frequencies associated with the geometry of the resonant aperture.
Inventors
- 👤 Ervin J. Nalos
- 👤 James C. Axtell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:03
CPC Classifications
H; H01; H01Q; H01Q15/00; H01Q15/14; H01Q15/148; H01Q13/00; H01Q13/10; H01Q13/103; H01Q3/00; H01Q3/44
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
93 words
A threshold energy, microwave switchable, electromagnetic energy reflecting surface comprising: a surface member having first surface portions reflective of electromagnetic energy and second surface portions including a sufficient number of polarization insensitive elements to render said surface member invisible for at least one predetermined frequency band of incident electromagnetic energy; and threshold radiation sensitive means having a predetermined threshold intensity level and connected to each said element and rendering said element electrically conducting only when microwave radiation of at least said predetermined threshold intensity level is incident upon said threshold radiation sensitive means.
Claim 2
Dependent Claim
93 words
A threshold energy, microwave switchable, electromagnetic energy reflecting surface comprising: a surface member having first surface portions reflective of electromagnetic energy and second surface portions including a sufficient number of polarization insensitive elements to render said surface member invisible for at least one predetermined frequency band of incident electromagnetic energy; and threshold radiation sensitive means having a predetermined threshold intensity level and connected to each said element and rendering said element electrically conducting only when microwave radiation of at least said predetermined threshold intensity level is incident upon said threshold radiation sensitive means.
Claim 3
Dependent Claim
106 words
A threshold energy, microwave switchable, electromagnetic energy reflecting surface, comprising: a surface member having a first surface portion reflective of electromagnetic energy; a plurality of polarization insensitive elements forming an array of second surface portions on said surface member for rendering said surface member invisible for at least one predetermined frequency band of incident electromagnetic energy; and threshold radiation sensitive means connected to said elements for rendering said elements electrically conducting only when microwave radiation at or above the threshold intensity level of said means is incident upon said means whereby said surface member is rendered reflective of incident electromagnetic energy at said predetermined frequency band.
Claim 4
Dependent Claim
106 words
A threshold energy, microwave switchable, electromagnetic energy reflecting surface, comprising: a surface member having a first surface portion reflective of electromagnetic energy; a plurality of polarization insensitive elements forming an array of second surface portions on said surface member for rendering said surface member invisible for at least one predetermined frequency band of incident electromagnetic energy; and threshold radiation sensitive means connected to said elements for rendering said elements electrically conducting only when microwave radiation at or above the threshold intensity level of said means is incident upon said means whereby said surface member is rendered reflective of incident electromagnetic energy at said predetermined frequency band.
Claim 5
Dependent Claim
25 words
An energy reflecting surface as recited in claim 2, wherein said polarization insensitive elements are formed by a set of apertures in said surface member.
Claim 6
Dependent Claim
24 words
An energy reflecting surface as recited in claim 3, wherein each said aperture is formed by three elongated openings emanating from a common point.
Claim 7
Dependent Claim
20 words
An energy reflecting surface as recited in claim 3, wherein each said aperture is formed by two intersecting elongated openings.
Claim 8
Dependent Claim
23 words
An energy reflecting surface as recited in claim 2, wherein said threshold radiation sensitive means comprises at least one non-linear solid state semiconductor.
Claim 9
Dependent Claim
20 words
An energy reflecting surface as recited in claim 2, wherein said threshold radiation sensitive means comprises at least one diode.
Claim 10
Dependent Claim
22 words
An energy reflecting surface as recited in claim 2, wherein each said threshold radiation sensitive means comprises at least one PIN diode.
Claim 11
Dependent Claim
55 words
An energy reflecting surface as recited in claim 2, wherein said surface member comprises a first outside layer reflective of electromagnetic energy and receiving said polarization insensitive elements, a second outside layer reflective of electromagnetic energy; and an intermediate layer of a lossy dielectric positioned intermediate said first outside layer and said second outside layer.
Claim 12
Dependent Claim
17 words
An energy reflecting surface as recited in claim 2, wherein said surface member is planar in shape.
Claim 13
Dependent Claim
17 words
An energy reflecting surface as recited in claim 2, wherein said surface member is curved in shape.
Claim 14
Dependent Claim
17 words
An energy reflecting surface as recited in claim 2, wherein said surface member is parabolic in shape.
Claim 15
Dependent Claim
25 words
An energy reflecting surface as recited in claim 11 or 12, also including means for focusing incident electromagnetic energy upon predetermined portions of said surface.
Claim 16
Dependent Claim
68 words
A remotely switchable, electromagnetic energy, reflector, comprising: a surface reflective of electromagnetic energy; an array of radiating elements provided in said surface with selective transmission and reflection properties; and means for electrically decoupling said array of radiating elements from said surface for making said surface entirely reflecting, wherein said decoupling means is operative only at or above a preselected threshold level of electromagnetic energy incident upon said surface.
Claim 17
Dependent Claim
68 words
A remotely switchable, electromagnetic energy, reflector, comprising: a surface reflective of electromagnetic energy; an array of radiating elements provided in said surface with selective transmission and reflection properties; and means for electrically decoupling said array of radiating elements from said surface for making said surface entirely reflecting, wherein said decoupling means is operative only at or above a preselected threshold level of electromagnetic energy incident upon said surface.
References Cited (Backward Citations)
US2880310A
Cited
GB814310A
Cited
US3392393A
Cited
US3148370A
Cited
US3231892A
Cited
US3257659A
Cited
US3305863A
Cited
US3308464A
Cited
US3568194A
Cited
US3789404A
Cited
US3535543A
Cited
US3703723A
Cited
US3623091A
Cited
US3896440A
Cited
US3769623A
Cited
US3842421A
Cited
US4021813A
Cited
US3975738A
Cited
US4125841A
Cited
US4126866A
Cited
US4148032A
Cited
US4320404A
Cited
US4160254A
Cited
US4314249A
Cited
EP0074295A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-09-13 | 1997-03-15 | 1997-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-09-13 | 2001-03-15 | 2001-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-09-13 | 2005-03-15 | 2005-09-14 | $7700.00 | Window Closed / Lapsed |