Patent US5204685A successfully refreshed from Google Patents.
US5204685A
Expired / Lapsed
US
⏱️ 0.0 years remaining
ARC range test facility
Assignee: United States Department of the Air Force
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Filing: 1992-07-01
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Granted: 1993-04-20
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Expires: 2012-07-01
Abstract
Abstract In order to measure the far field antenna pattern of a phased array antenna, the phased array is focused at a probe antenna which is a specific distance away from the aperture. The antenna pattern is then measured by moving the probe antenna on a constant focal arc. This arc minimizes phase aberrations due to defocusing error. To minimize amplitude errors, the pattern of the probe antenna is carefully matched to compensate for the variation induced amplitude error.
Inventors
- 👤 Peter R. Franchi
- 👤 Harvey E. Tobin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:48
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/08; G01R29/10
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
156 words
A process for measuring a phased array antenna's far field antenna pattern which is exhibited as electromagnetic power measured in watts per square centimeter by a beam emitted by the phased array antenna wherein said phased array antenna has an antenna center, said process comprising the steps of: focusing the beam onto a probe antenna which measures the beam, said probe antenna being positioned at a distance R, where R is a distance between said probe antenna and the antenna center of the phased array antenna given by ##EQU38## where: is measure of the phased array antenna's aperture and λ is a measure of operational wavelength of the beam; measuring the electromagnetic power of the beam with the probe antenna to identify a pattern of electromagnetic power emitted there from; moving the probe antenna to different positions that are on a focal arc of the phased array antenna; and repeating the focusing, measuring and moving steps.
Claim 2
Dependent Claim
156 words
A process for measuring a phased array antenna's far field antenna pattern which is exhibited as electromagnetic power measured in watts per square centimeter by a beam emitted by the phased array antenna wherein said phased array antenna has an antenna center, said process comprising the steps of: focusing the beam onto a probe antenna which measures the beam, said probe antenna being positioned at a distance R, where R is a distance between said probe antenna and the antenna center of the phased array antenna given by ##EQU38## where: is measure of the phased array antenna's aperture and λ is a measure of operational wavelength of the beam; measuring the electromagnetic power of the beam with the probe antenna to identify a pattern of electromagnetic power emitted there from; moving the probe antenna to different positions that are on a focal arc of the phased array antenna; and repeating the focusing, measuring and moving steps.
Claim 3
Dependent Claim
40 words
A process, as defined in claim 1, wherein said moving step is accomplished by repositioning the probe antenna along different positions on a curve given by R cos θ where θ is an angle from broadside to the probe antenna.
Claim 4
Dependent Claim
26 words
A process, as defined in claim 1, where D/λ is up to 20 and where R/λ in said focusing step is between about 89 and 800.
Claim 5
Dependent Claim
21 words
A process, as defined in claim 1, where D/λ is up to 40 and R/λ is between about 253 and 3,200.
Claim 6
Dependent Claim
18 words
A process, as defined in claim 1, where about 60 and R/λ is between about 465 and 7,200.
Claim 7
Dependent Claim
26 words
A process, as defined in claim 2, where D/λ is up to 20 and where R/λ in said focusing step is between about 89 and 800.
Claim 8
Dependent Claim
21 words
A process, as defined in claim 2, where D/λ is up to 40 and R/λ is between about 253 and 3,200.
Claim 9
Dependent Claim
22 words
A process, as defined in claim 2, where D/λ is up to about 60 and R/λ is between about 465 and 7,200.
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) | 1996-04-19 | 1996-10-19 | 1997-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-19 | 2000-10-19 | 2001-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-19 | 2004-10-19 | 2005-04-20 | $7700.00 | Window Closed / Lapsed |