US4970634A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radar transparent materials
Assignee: Plessey Overseas Ltd
•
Filing: 1989-05-25
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Granted: 1990-11-13
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Expires: 2009-05-25
Abstract
Abstract A structure for reflecting visible light or near visible light, wherein the structure is formed of a low dielectric constant material having an external surface comprising an electrically conductive layer of material which has an array of slots therein so as to be substantially transparent to microwave radiation of a predetermined wavelength which will impinge upon the structure during use, while being reflective to light.
Inventors
- 👤 William G. Howell
- 👤 Frederick S. Ward
- 👤 John F. Graver
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:44
CPC Classifications
H; H01; H01Q; H01Q15/00; H01Q15/0006; H01Q15/0013; H01Q1/00; H01Q1/42
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
76 words
A structure for reflecting visible light or near visible light, wherein the structure is formed of a low dielectric constant material having an external light reflector surface comprising an electrically conductive layer of material which has an array of slots therein so as to be substantially transparent to microwave radiation of a predetermined wavelength which will impinge upon the structure during use, whilst being reflective to light emitted from a light source associated with said structure.
Claim 2
Dependent Claim
76 words
A structure for reflecting visible light or near visible light, wherein the structure is formed of a low dielectric constant material having an external light reflector surface comprising an electrically conductive layer of material which has an array of slots therein so as to be substantially transparent to microwave radiation of a predetermined wavelength which will impinge upon the structure during use, whilst being reflective to light emitted from a light source associated with said structure.
Claim 3
Dependent Claim
24 words
A structure as claimed in claim 1 or wherein the light reflector surface is formed of a metal layer deposited on a plastics surface.
Claim 4
Dependent Claim
48 words
A structure as claimed in claim 1 wherein the low dielectric constant material comprises a plastics surface which has ribs formed therein in the pattern of said array of slots, and said slots are formed by grinding down the ribs subsequent to forming said electrically conductive layer thereon.
Claim 5
Dependent Claim
19 words
A structure as claimed in claim 1 wherein said array of slots comprises a regular array of elemental areas.
Claim 6
Dependent Claim
15 words
A structure as claimed in claim 5 wherein each area includes a tripolar slot configuration.
Claim 7
Dependent Claim
47 words
A structure as claimed in claim 1 wherein said array of slots is such that, when the reflector surface is formed on a non-planar, for example parabolic surface, the surface provides to incoming radiation, a regular array of elemental areas, each area including a tripolar slot configuration.
Claim 8
Dependent Claim
37 words
A structure as claimed in claim 1 including a plurality of said electrically conductive layers stacked one upon the other and separated by a predetermined distance in order to widen the pass band for incident microwave radiation.
Claim 9
Dependent Claim
29 words
A structure as claimed in claim 1 wherein the array of slots comprises a regular array of elemental areas, each area including a slotted configuration defining a tripolar slot.
Claim 10
Dependent Claim
34 words
A structure as claimed in claim 1 wherein the array of slots comprises a regular array of elemental areas, each area including a slotted configuration defining a tripolar slot projected onto a parabolic surface.
Claim 11
Dependent Claim
29 words
A structure as claimed in claim 1 wherein the array of slots comprises a regular array of elemental areas, each area including a slotted configuration defining a disc shape.
Claim 12
Dependent Claim
29 words
A structure as claimed in claim 1 wherein the array of slots comprises a regular array of elemental areas, each area including a slotted configuration defining a hexagon shape.
Claim 13
Dependent Claim
29 words
A structure as claimed in claim 1 wherein the array of slots comprises a regular array of elemental areas, each area including a slotted configuration defining a triangle shape.
Claim 14
Dependent Claim
29 words
A structure as claimed in claim 1 wherein the array of slots comprises a regular array of elemental areas, each area including a slotted configuration defining a bar shape.
Claim 15
Dependent Claim
30 words
A structure as claimed in claim 1 wherein the array of slots comprises a regular array of elemental areas, each area including a slotted configuration defining a tripolar bow shape.
Claim 16
Dependent Claim
38 words
A structure as claimed in claim 1 wherein the array of slots comprises a regular array of elemental areas, each area including a slotted configuration defining a disc shape joined to its nearest neighbours by conductive line portions.
Claim 17
Dependent Claim
39 words
A structure as claimed in claim 1 wherein the array of slots comprises a regular array of elemental areas, each area including a slotted configuration defining a disc shape disclosed within a rectangular frame defined by conductive line portions.
Claim 18
Dependent Claim
16 words
A light as claimed in claim 1 mounted on a mast structure comprising a rotatable tripod.
Claim 19
Dependent Claim
65 words
An airfield approach landing light and supporting structure therefor being formed of low dielectric constant plastics material and having an external light reflector surface comprising a layer of electrically conductive material which has an array of slots therein such as to be substantially transparent to microwave radiation of a predetermined frequency whilst being reflective to light emitted from a light source associated with said structure.
Claim 20
Dependent Claim
65 words
An airfield approach landing light and supporting structure therefor being formed of low dielectric constant plastics material and having an external light reflector surface comprising a layer of electrically conductive material which has an array of slots therein such as to be substantially transparent to microwave radiation of a predetermined frequency whilst being reflective to light emitted from a light source associated with said structure.
Claim 21
Dependent Claim
28 words
A light as claimed in claim 18 wherein a filament of the light source and/or bulb electric contacts are arranged perpendicular to a direction of incident microwave radiation.
Claim 22
Dependent Claim
24 words
A light as claimed in claim 18 wherein a holder for said light bulb is formed of a ceramics material transparent to microwave radiation.
Claim 23
Dependent Claim
28 words
A light as claimed in claim 18 including a transparent light lens formed of a plastics material having an insertion loss of less than 1db for microwave radiation.
Claim 24
Dependent Claim
20 words
A light as claimed in claim 18 wherein the housing for the light is formed of non-conductive dielectric plastics material.
References Cited (Backward Citations)
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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) | 1993-11-12 | 1994-05-14 | 1994-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-12 | 1998-05-14 | 1998-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-12 | 2002-05-14 | 2002-11-13 | $7700.00 | Window Closed / Lapsed |