US3924239A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dichroic plate
Assignee: National Aeronautics and Space Administration
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Filing: 1974-06-27
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Granted: 1975-12-02
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Expires: 1994-06-27
Abstract
Abstract A dichroic plate is disclosed for passing radiation within a particular frequency band and reflecting radiation outside of that frequency band. The value of the thickness of the plate is selected so that the plate acts as a resonant narrow band pass filter for the desired pass frequency, and the shapes of the apertures in the dichroic plate are selected to compensate for the phase shift caused by the air-plate interface presented to the signals passing therethrough.
Inventors
- 👤 James C Administrator Fletcher
- 👤 Philip D Potter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:17
CPC Classifications
H; H01; H01Q; H01Q15/00; H01Q15/0006; H01Q15/0013
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
99 words
A dichroic reflector plate of the type which reflects signals having a first frequency and passes signals therethrough having a second frequency, said reflector plate comprising a conductive plate having a pattern of holes therethrough, said conductive plate having a thickness which provides a resonant band pass response to signals including signals having said second frequency, said conductive plate having a thickness which is substantially equal to one-half the wave length which said second signal would have within a wave guide which has the same shaped aperture therethrough as the shape of an aperture through said dichroic reflector plate.
Claim 2
Dependent Claim
99 words
A dichroic reflector plate of the type which reflects signals having a first frequency and passes signals therethrough having a second frequency, said reflector plate comprising a conductive plate having a pattern of holes therethrough, said conductive plate having a thickness which provides a resonant band pass response to signals including signals having said second frequency, said conductive plate having a thickness which is substantially equal to one-half the wave length which said second signal would have within a wave guide which has the same shaped aperture therethrough as the shape of an aperture through said dichroic reflector plate.
Claim 3
Dependent Claim
15 words
A dichoric reflector plate as recited in claim 1 wherein the apertures therethrough are circular.
Claim 4
Dependent Claim
23 words
A dichroic reflector plate as recited in claim 1 wherein the apertures therethrough are circularly shaped except for two opposite parallel flat regions.
Claim 5
Dependent Claim
56 words
In a dichroic plate reflector, having apertures therethrough, the method of compensating for undesIrable phase shift caused to signals passing through said apertures by the free space to aperture transition discontinuities, comprising shaping the cross section of each aperture which extends through said plate into a circle except for two opposite sides thereof which are flattened.
Claim 6
Dependent Claim
56 words
In a dichroic plate reflector, having apertures therethrough, the method of compensating for undesIrable phase shift caused to signals passing through said apertures by the free space to aperture transition discontinuities, comprising shaping the cross section of each aperture which extends through said plate into a circle except for two opposite sides thereof which are flattened.
Claim 7
Dependent Claim
57 words
In a dichroic plate reflector, having apertures therethrough, the method of improving the efficiency of transmission therethrough of desired signals comprising establishing the thickness of said dichroic plate at a value equal to one half of the wavelength of said signals in a wave guide having the same cross section as the apertures in said dichroic plate.
Claim 8
Dependent Claim
57 words
In a dichroic plate reflector, having apertures therethrough, the method of improving the efficiency of transmission therethrough of desired signals comprising establishing the thickness of said dichroic plate at a value equal to one half of the wavelength of said signals in a wave guide having the same cross section as the apertures in said dichroic plate.
Claim 9
Dependent Claim
84 words
In a dichroic plate reflector having apertures therethrough, the method of improving the efficiency of signal transmission and reducing the polarization degradation caused to signals passing therethrough comprising making said dichroic plate thickness equal to one half of the wavelength of said signals in a wave guide having the same cross section as an aperture in said dichroic plate, and shaping the cross section of each aperture in said dichroic plate into a circle except for flat sections at opposite ends of one radius.
Claim 10
Dependent Claim
84 words
In a dichroic plate reflector having apertures therethrough, the method of improving the efficiency of signal transmission and reducing the polarization degradation caused to signals passing therethrough comprising making said dichroic plate thickness equal to one half of the wavelength of said signals in a wave guide having the same cross section as an aperture in said dichroic plate, and shaping the cross section of each aperture in said dichroic plate into a circle except for flat sections at opposite ends of one radius.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |