Patent US4241351A successfully refreshed from Google Patents.
US4241351A
Expired / Lapsed
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Array antenna controller
Assignee: United States Department of the Army
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Filing: 1979-05-11
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Granted: 1980-12-23
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Expires: 1999-05-11
Abstract
Abstract A coherent optical processor antenna controller for controlling the patternmitted by an array antenna. Since the amplitude and phase of the antenna excitation signals are related to the far field by the Fourier transform function, a coherent optical processor, which uses lenses to take the Fourier transforms of images may be used to control the antenna excitation. The shape and direction of the pattern may be controlled by the transmittance distribution of a transparency in the processor and a null may be formed by the utilization of an additional slide.
Inventors
- 👤 James S. Shreve
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:00
CPC Classifications
H; H01; H01Q; H01Q3/00; H01Q3/26; H01Q3/2676; H01Q3/2605; H01Q3/2611
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
132 words
An apparatus for causing an array antenna to transmit a selected antenna pattern, said array antenna having a plurality of array elements comprising, a first transparency which varies in transmittance in accordance with a parameter of said selected antenna pattern, optical processor means including both means for directing a coherent light beam through said transparency so that said beam is spatially modulated by said variation in transmittance and means for taking the Fourier transform of said modulated beam, thus forming a resultant beam, means for providing electrical signals corresponding to the amplitude and/or phase of a plurality of spatially displaced samples of said resultant beam, said samples corresponding in relative spacing to the elements of said array antenna, and means for exciting the elements of said array antenna with said electrical signals.
Claim 2
Independent Claim
132 words
An apparatus for causing an array antenna to transmit a selected antenna pattern, said array antenna having a plurality of array elements comprising, a first transparency which varies in transmittance in accordance with a parameter of said selected antenna pattern, optical processor means including both means for directing a coherent light beam through said transparency so that said beam is spatially modulated by said variation in transmittance and means for taking the Fourier transform of said modulated beam, thus forming a resultant beam, means for providing electrical signals corresponding to the amplitude and/or phase of a plurality of spatially displaced samples of said resultant beam, said samples corresponding in relative spacing to the elements of said array antenna, and means for exciting the elements of said array antenna with said electrical signals.
Claim 3
Dependent Claim
15 words
The apparatus of claim 1, wherein said parameter of said selected antenna pattern is directivity.
Claim 4
Dependent Claim
22 words
The apparatus of claim 2, wherein said and said means for taking the Fourier transform of said modulated beam comprises a lens.
Claim 5
Dependent Claim
25 words
The apparatus of claim 3 wherein said means for providing electrical signals corresponding to a plurality of spatially displaced samples includes a pinhole array means.
Claim 6
Dependent Claim
32 words
The apparatus of claim 4 further including a second transparency, located between said first transparency and said lens, said second transparency ideally spatially varying in transmittance in accordance with a cosine function.
Claim 7
Dependent Claim
17 words
The apparatus of claim 5 further including means for producing a null in said selected antenna pattern.
Claim 8
Dependent Claim
45 words
The apparatus of claim 6 wherein said means for producing a null includes a further transparency having an opaque spot, said further transparency being disposed in the same optical path as said pinhole array means, but being separated from said array means by lens means.
References Cited (Backward Citations)
US4119969A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |