US4894488A
Expired / Lapsed
US
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High frequency signal cable with improved electrical dissipation factor and method of producing same
Assignee: COMM/SCOPE Inc A CORP OF
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Filing: 1989-02-10
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Granted: 1990-01-16
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Expires: 2009-02-10
Abstract
Abstract A cable and method for making such cable is disclosed. The cable is especially suited for high frequency applications in which electrical attenuation and dissipation factor are of critical importance. The cable comprises a tubular outer conductor, and at least one inner conductor for transmission of electrical signals. Between the inner and outer conductor is a foamed dielectric material. This dielectric is formed from the extrusion of an olefin polymer or a fluoropolymer with a blowing agent gas. Sulfurhexafluoride (SF 6 ), rather than environmentally unsafe chlorofluorocarbons, is used as a blowing agent to foam the dielectric.
Inventors
- 👤 Chakra V. Gupta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:23
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/44; C; C08; C08J; C08J9/00; C08J9/04; C08J9/12; H01B11/00; H01B11/18; H01B11/1834; H01B11/1839; H01B13/00; H01B13/06; H01B13/14; H01B13/142; H01B7/00; H01B7/02; H01B7/0233
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
66 words
A high frequency signal cable having improved electrical attenuation properties, comprising at least one inner signal conductor, an outer shielding conductor surrounding said at least one inner signal conductor, and a foam dielectric disposed between said inner signal conductor and said outer shielding conductor, said foam dielectric comprising a polymer matrix having a multiplicity of cells formed therein, said cells containing residual blowing agent comprising sulfurhexafluoride.
Claim 2
Dependent Claim
66 words
A high frequency signal cable having improved electrical attenuation properties, comprising at least one inner signal conductor, an outer shielding conductor surrounding said at least one inner signal conductor, and a foam dielectric disposed between said inner signal conductor and said outer shielding conductor, said foam dielectric comprising a polymer matrix having a multiplicity of cells formed therein, said cells containing residual blowing agent comprising sulfurhexafluoride.
Claim 3
Dependent Claim
18 words
A cable according to claim 1 wherein the foam dielectric has an expansion ratio of 2 or greater.
Claim 4
Dependent Claim
18 words
A cable according to claim 1 wherein said blowing agent comprises sulfurhexafluoride and at least one other gas.
Claim 5
Dependent Claim
20 words
A cable according to claim 1 wherein said cells additionally comprise the residue of a thermally decomposable chemical blowing agent.
Claim 6
Dependent Claim
13 words
A cable according to claim 1 wherein said polymer comprises a polyolefin polymer.
Claim 7
Dependent Claim
38 words
A cable according to claim 5 wherein the polyolefin polymer comprises polyethylene having a density of 0.91 to 0.97 grams per cubic centimeter, and the foamed polymer has a density of 0.5 grams per cubic centimeter or less.
Claim 8
Dependent Claim
12 words
A cable according to claim 1 wherein said polymer comprises a fluoropolymer.
Claim 9
Dependent Claim
13 words
A cable according to claim 7 wherein the fluoropolymer comprises fluorinated ethylene-propylene polymer.
Claim 10
Dependent Claim
37 words
A cable according to claim 8 wherein the fluorinated ethylene-propylene polymer has a density of 1.9 to 2.2 grams per cubic centimeter, and the foamed polymer has a density of 1.1 grams per cubic centimeter or less.
Claim 11
Dependent Claim
13 words
A cable according to claim 7 wherein the fluoropolymer comprises perfluoro alkoxy copolymer.
Claim 12
Dependent Claim
32 words
A cable as defined in claim 1 which comprises a single inner signal conductor surrounded by said outer shielding conductor, and wherein the inner conductor is disposed coaxially with said outer conductor.
Claim 13
Dependent Claim
21 words
A cable as defined in claim 1 which comprises a plurality of inner signal conductors surrounded by said outer shielding conductor.
Claim 14
Dependent Claim
74 words
A high frequency signal cable having improved electrical attenuation properties, comprising at least one inner conductor, a tubular outer conductor surrounding said at least one inner conductor, and a foam dielectric disposed between said at least one inner conductor and said outer conductor, said foam dielectric having an expansion ratio of 2 or greater and comprising a polyethylene polymer matrix having a multiplicity of closed cells formed therein, said cells containing sulfurhexafluoride blowing agent.
Claim 15
Dependent Claim
74 words
A high frequency signal cable having improved electrical attenuation properties, comprising at least one inner conductor, a tubular outer conductor surrounding said at least one inner conductor, and a foam dielectric disposed between said at least one inner conductor and said outer conductor, said foam dielectric having an expansion ratio of 2 or greater and comprising a polyethylene polymer matrix having a multiplicity of closed cells formed therein, said cells containing sulfurhexafluoride blowing agent.
Claim 16
Dependent Claim
75 words
A high frequency signal cable having improved electrical attenuation properties, comprising at least one inner conductor, a tubular outer conductor surrounding said at least one inner conductor, and a foam dielectric disposed between said at least one inner conductor and said outer conductor, said foam dielectric having an expansion ratio of 2 or greater and comprising a fluorinated ethylene-propylene polymer matrix having a multiplicity of closed cells formed therein, said cells containing sulfurhexafluoride blowing agent.
Claim 17
Dependent Claim
75 words
A high frequency signal cable having improved electrical attenuation properties, comprising at least one inner conductor, a tubular outer conductor surrounding said at least one inner conductor, and a foam dielectric disposed between said at least one inner conductor and said outer conductor, said foam dielectric having an expansion ratio of 2 or greater and comprising a fluorinated ethylene-propylene polymer matrix having a multiplicity of closed cells formed therein, said cells containing sulfurhexafluoride blowing agent.
Claim 18
Dependent Claim
44 words
A cable dielectric for high frequency signal cables comprising a foamed polymer having an expansion ratio of 2 or greater and comprising a foamed fluorinated ethylene-propylene polymer matrix having a multiplicity of closed cells formed therein, and sulfurhexafluoride blowing agent contained within said cells.
Claim 19
Dependent Claim
44 words
A cable dielectric for high frequency signal cables comprising a foamed polymer having an expansion ratio of 2 or greater and comprising a foamed fluorinated ethylene-propylene polymer matrix having a multiplicity of closed cells formed therein, and sulfurhexafluoride blowing agent contained within said cells.
Claim 20
Dependent Claim
19 words
A cable dielectric according to claim 15 wherein said foamed polymer has an expansion ratio of 2.3 or greater.
Claim 21
Independent Claim
58 words
A method of producing a high frequency signal cable with improved electrical attenuation properties at high frequencies which comprises extruding a mixture of a molten polymer and a blowing agent comprising sulfurhexafluoride around at least one inner signal conductor, expanding the mixture to form a foam dielectric, and applying an outer shielding conductor around the expanded foam dielectric.
Claim 22
Independent Claim
58 words
A method of producing a high frequency signal cable with improved electrical attenuation properties at high frequencies which comprises extruding a mixture of a molten polymer and a blowing agent comprising sulfurhexafluoride around at least one inner signal conductor, expanding the mixture to form a foam dielectric, and applying an outer shielding conductor around the expanded foam dielectric.
Claim 23
Dependent Claim
21 words
The method according to claim 17 wherein the blowing agent comprises a mixture of sulfurhexafluoride and at least one other gas.
Claim 24
Dependent Claim
22 words
The method according to claim 17 wherein the blowing agent comprises a mixture of sulfurhexafluoride and a thermally decomposable chemical blowing agent.
Claim 25
Dependent Claim
13 words
The method according to claim 17 wherein the polymer comprises a polyolefin polymer.
Claim 26
Dependent Claim
12 words
The method according to claim 20 wherein the polyolefin polymer is polyethylene.
Claim 27
Dependent Claim
12 words
The method according to claim 17 wherein the polymer comprises a fluoropolymer.
Claim 28
Dependent Claim
13 words
The method according to claim 22 wherein the fluoropolymer comprises fluorinated ethylene-propylene polymer.
Claim 29
Dependent Claim
13 words
The method according to claim 22 wherein the fluoropolymer comprises perfluoro alkoxy copolymer.
Claim 30
Dependent Claim
25 words
The method according to claim 17 wherein the step of expanding the mixture comprises expanding the mixture to an expansion ratio of 2 or greater.
Claim 31
Independent Claim
78 words
A method of providing improved electrical attenuation properties in a signal cable, which comprises: providing a cable having at least one inner signal conductor, an outer shielding conductor surrounding the inner signal conductor, and a foam dielectric disposed between the inner signal conductor and the outer shielding conductor comprised of a polymer matrix having a multiplicity of cells formed therein by a blowing agent containing sulfurhexafluoride, and transmitting high frequency RF or microwave signals through said signal cable.
Claim 32
Independent Claim
78 words
A method of providing improved electrical attenuation properties in a signal cable, which comprises: providing a cable having at least one inner signal conductor, an outer shielding conductor surrounding the inner signal conductor, and a foam dielectric disposed between the inner signal conductor and the outer shielding conductor comprised of a polymer matrix having a multiplicity of cells formed therein by a blowing agent containing sulfurhexafluoride, and transmitting high frequency RF or microwave signals through said signal cable.
Claim 33
Dependent Claim
21 words
The method according to claim 26 wherein the blowing agent comprises a mixture of sulfurhexafluoride and at least one other gas.
Claim 34
Dependent Claim
13 words
The method according to claim 26 wherein the polymer comprises a polyolefin polymer.
Claim 35
Dependent Claim
12 words
The method according to claim 28 wherein the polyolefin polymer is polyethylene.
Claim 36
Dependent Claim
12 words
The method according to claim 26 wherein the polymer comprises a fluoropolymer.
Claim 37
Dependent Claim
13 words
The method according to claim 30 wherein the fluoropolymer comprises fluorinated ethylene-propylene polymer.
Claim 38
Dependent Claim
61 words
A high frequency signal cable having improved electrical attenuation properties, comprising at least one inner signal conductor, an outer shielding conductor surrounding said at least one signal conductor, and a foam dielectric disposed between said signal conductor and said shielding conductor, said foam dielectric comprising a polymer matrix having a multiplicity of cells formed therein by a blowing agent containing sulfurhexafluoride.
Claim 39
Dependent Claim
61 words
A high frequency signal cable having improved electrical attenuation properties, comprising at least one inner signal conductor, an outer shielding conductor surrounding said at least one signal conductor, and a foam dielectric disposed between said signal conductor and said shielding conductor, said foam dielectric comprising a polymer matrix having a multiplicity of cells formed therein by a blowing agent containing sulfurhexafluoride.
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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) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-15 | 1997-07-17 | 1998-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-15 | 2001-07-17 | 2002-01-16 | $7700.00 | Window Closed / Lapsed |