US3716869A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Millimeter wave antenna system
Assignee: National Aeronautics and Space Administration
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Filing: 1970-12-02
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Granted: 1973-02-13
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Expires: 1990-12-02
Abstract
Abstract A millimeter wave antenna mounted on a satellite includes a parabolic reflector fabricated of carbon fiber reinforced plastic (CFRP) composite material to enable the parabolic shape of the reflector to be maintained to within three percent of a millimeter wave length despite possible temperature variations on the order of 300* F. between portions of the reflector illuminated by the sun and in the umbra. Waveguides, fabricated from CFRP, for a feed positioned approximately at the focal point of the reflector are the sole mechanical supporting means for the feed. To take advantage of the physical properties of the carbon fiber reinforced plastic composite materials a honeycomb structure is sandwiched between layers of the CFRP. The surface of the reflector illuminated by the feed is coated with a thin film of aluminum which functions as a millimeter wave reflector. The waveguide CFRP interior is coated with a thin film of aluminum to provide the millimeter wave conducting surface.
Inventors
- 👤 W Gould
- 👤 J Evans
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:52
CPC Classifications
H; H01; H01Q; H01Q19/00; H01Q19/10; H01Q19/18; H01Q19/19; H01Q1/00; H01Q15/00; H01Q15/14; H01Q15/141; H01Q15/142; H01Q15/144; H01Q15/16; H01Q25/00; H01Q25/002
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
149 words
An antenna system on a spacecraft outside at the atmosphere and thereby subject to temperature differences of 300* F. between surfaces exposed to sunlight and shaded from sunlight comprising a reflecting dish having a focal point, said dish being mounted on the spacecraft, said dish being fabricated from carbon fiber reinforced plastic (CFRP) composite materials, a millimeter wave feed illuminating said reflector and effectively located at said focal point, waveguide means for exciting the feed extending between the dish and the feed, said waveguide means including a shaft having a hollow honeycomb core, first and second CFRP laminates respectively bonded to the inner and outer surfaces of the core, and an electrically conducting surface on the first CFRP laminate forming a guiding structure for waves exciting the feed and, a reflecting metal layer covering substantially the entire carbon fiber reinforced plastic surface of the reflector illuminated by the feed.
Claim 2
Dependent Claim
149 words
An antenna system on a spacecraft outside at the atmosphere and thereby subject to temperature differences of 300* F. between surfaces exposed to sunlight and shaded from sunlight comprising a reflecting dish having a focal point, said dish being mounted on the spacecraft, said dish being fabricated from carbon fiber reinforced plastic (CFRP) composite materials, a millimeter wave feed illuminating said reflector and effectively located at said focal point, waveguide means for exciting the feed extending between the dish and the feed, said waveguide means including a shaft having a hollow honeycomb core, first and second CFRP laminates respectively bonded to the inner and outer surfaces of the core, and an electrically conducting surface on the first CFRP laminate forming a guiding structure for waves exciting the feed and, a reflecting metal layer covering substantially the entire carbon fiber reinforced plastic surface of the reflector illuminated by the feed.
Claim 3
Dependent Claim
149 words
An antenna system on a spacecraft outside at the atmosphere and thereby subject to temperature differences of 300* F. between surfaces exposed to sunlight and shaded from sunlight comprising a reflecting dish having a focal point, said dish being mounted on the spacecraft, said dish being fabricated from carbon fiber reinforced plastic (CFRP) composite materials, a millimeter wave feed illuminating said reflector and effectively located at said focal point, waveguide means for exciting the feed extending between the dish and the feed, said waveguide means including a shaft having a hollow honeycomb core, first and second CFRP laminates respectively bonded to the inner and outer surfaces of the core, and an electrically conducting surface on the first CFRP laminate forming a guiding structure for waves exciting the feed and, a reflecting metal layer covering substantially the entire carbon fiber reinforced plastic surface of the reflector illuminated by the feed.
Claim 4
Dependent Claim
149 words
An antenna system on a spacecraft outside at the atmosphere and thereby subject to temperature differences of 300* F. between surfaces exposed to sunlight and shaded from sunlight comprising a reflecting dish having a focal point, said dish being mounted on the spacecraft, said dish being fabricated from carbon fiber reinforced plastic (CFRP) composite materials, a millimeter wave feed illuminating said reflector and effectively located at said focal point, waveguide means for exciting the feed extending between the dish and the feed, said waveguide means including a shaft having a hollow honeycomb core, first and second CFRP laminates respectively bonded to the inner and outer surfaces of the core, and an electrically conducting surface on the first CFRP laminate forming a guiding structure for waves exciting the feed and, a reflecting metal layer covering substantially the entire carbon fiber reinforced plastic surface of the reflector illuminated by the feed.
Claim 5
Dependent Claim
30 words
The antenna system of claim 1 wherein the dish is fabricated from a honeycomb core having a planar face on which there is bonded a laminate including a CFRP sheet.
Claim 6
Dependent Claim
44 words
The antenna system of claim 2 wherein the laminate includes a plurality of CFRP sheets, each of said sheets having isotropic longitudinally directed fibers of CFRP, adjacent ones of said sheets being bonded together and having the fibers thereof extending at mutually right angles.
Claim 7
Dependent Claim
26 words
The antenna system of claim 3 wherein the metal layer is deposited on the surface of the laminate illuminated by the millimeter waves exciting the feed.
Claim 8
Dependent Claim
17 words
The antenna system of claim 4 wherein a silicon oxide layer is deposited on the metal layer.
Claim 9
Dependent Claim
34 words
The antenna system of claim 1 wherein the dish is fabricated from a honeycomb core having a pair of planar faces on each of which there is bonded a laminate including a CFRP sheet.
Claim 10
Dependent Claim
45 words
The antenna system of claim 6 wherein each of the laminates includes a plurality of CFRP sheets, each of said sheets having isotropic longitudinally directed fibers of CFRP, adjacent ones of said sheets being bonded together and having the fibers thereof at mutually right angles.
Claim 11
Dependent Claim
91 words
An antenna system comprising a reflecting dish having a focal point, a feed positioned substantially at the focal point, waveguide means for exciting the feed extending between the perisphery of the dish and the feed and being the only means for mechanically supporting the feed, said waveguide means including a shaft having a hollow honeycomb core, first and second CFRP laminates respectively bonded to the inner and outer surfaces of the core, and an electrically conducting surfaces on the first CFRP laminate forming a guiding structure for waves exciting the feed.
Claim 12
Dependent Claim
91 words
An antenna system comprising a reflecting dish having a focal point, a feed positioned substantially at the focal point, waveguide means for exciting the feed extending between the perisphery of the dish and the feed and being the only means for mechanically supporting the feed, said waveguide means including a shaft having a hollow honeycomb core, first and second CFRP laminates respectively bonded to the inner and outer surfaces of the core, and an electrically conducting surfaces on the first CFRP laminate forming a guiding structure for waves exciting the feed.
Claim 13
Dependent Claim
33 words
The system of claim 8 wherein the waveguide means includes four struts positioned at mutually right angles to each other, and said feed includes four elements each excited by energy in said waveguides.
Claim 14
Dependent Claim
156 words
An antenna system on a spacecraft outside of the atmosphere and thereby subject to temperature differences of 300* F. between surfaces exposed to sunlight and shaded from sunlight comprising a first parabolic reflecting dish having a focal point and mounted on the spacecraft, a subreflector positioned between the dish and the focal point a first millimeter wave feed illuminating the subreflector and located in proximity with the dish, whereby the first feed, the subreflector and the first reflecting dish form a narrow beam Cassegrain antenna, a second millimeter wave feed positioned substantially at the focal point, waveguide means for exciting the second feed, a second parabolic reflecting dish back to back with the subreflector, and first and second reflecting dishes and said subreflector and waveguide means being fabricated from carbon fiber reinforced plastic (CFRP) composite materials, a reflecting metal layer covering substantially the entire carbon fiber reinforced plastic surface of the reflector illuminated by the feed.
Claim 15
Dependent Claim
156 words
An antenna system on a spacecraft outside of the atmosphere and thereby subject to temperature differences of 300* F. between surfaces exposed to sunlight and shaded from sunlight comprising a first parabolic reflecting dish having a focal point and mounted on the spacecraft, a subreflector positioned between the dish and the focal point a first millimeter wave feed illuminating the subreflector and located in proximity with the dish, whereby the first feed, the subreflector and the first reflecting dish form a narrow beam Cassegrain antenna, a second millimeter wave feed positioned substantially at the focal point, waveguide means for exciting the second feed, a second parabolic reflecting dish back to back with the subreflector, and first and second reflecting dishes and said subreflector and waveguide means being fabricated from carbon fiber reinforced plastic (CFRP) composite materials, a reflecting metal layer covering substantially the entire carbon fiber reinforced plastic surface of the reflector illuminated by the feed.
Claim 16
Dependent Claim
34 words
The antenna system of claim 10 wherein the waveguide meAns for exciting the other feed extending between the periphery of the dish and the feed is the only means for supporting the second feed.
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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) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |