Patent US3775765A successfully refreshed from Google Patents.
US3775765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for resolving the sizes and centroid locations of buried objects
Assignee: AT&T Inc
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Filing: 1971-12-08
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Granted: 1973-11-27
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Expires: 1991-12-08
Abstract
Abstract A broadband, radar-type system for resolving the sizes and centroid locations of objects buried at a maximum depth in the order of 6 to 10 feet is disclosed. The system uses a carrier frequency which is high enough so that an instantaneous bandwidth of about 25 percent provides resolution in the order of 1 foot. The system antenna includes impedance matching and focusing means. Polarization diversity of the transmitted beam may be accomplished to distinguish between elongated and generally round objects.
Inventors
- 👤 Piazza G Di
- 👤 P Onno
- 👤 H Oswald
- 👤 C Schaible
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:30
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/0209; G01V; G01V3/00; G01V3/12; G01S13/88; G01S13/885
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
145 words
Apparatus for detecting an object below the surface of the earth, said apparatus comprising a transmitter for generating a pulse modulated carrier wave, a receiver, an antenna assembly movable over said surface of said earth and having an output impedance approximately equal to that of said surface, an electrically controlled impedance matching means connected to said antenna assembly, and means for alternately connecting said transmitter and said receiver to said impedance matching means, said last-mentioned means comprising feedback control means responsive to energy through said lastmentioned means to control said impedance matching means to optimize the impedance match between said antenna assembly and said mean for connecting, and delay means to cause the transmission time from said transmitter to said antenna assembly to said receiver to equal a period at least equal to the duration of said pulse modulated carrier wave produced by said transmitter.
Claim 2
Dependent Claim
145 words
Apparatus for detecting an object below the surface of the earth, said apparatus comprising a transmitter for generating a pulse modulated carrier wave, a receiver, an antenna assembly movable over said surface of said earth and having an output impedance approximately equal to that of said surface, an electrically controlled impedance matching means connected to said antenna assembly, and means for alternately connecting said transmitter and said receiver to said impedance matching means, said last-mentioned means comprising feedback control means responsive to energy through said lastmentioned means to control said impedance matching means to optimize the impedance match between said antenna assembly and said mean for connecting, and delay means to cause the transmission time from said transmitter to said antenna assembly to said receiver to equal a period at least equal to the duration of said pulse modulated carrier wave produced by said transmitter.
Claim 3
Dependent Claim
30 words
Apparatus in accordance with claim 1 in which said feedback control means is further connected to said receiver to protect said receiver during periods when received signals exceed predetermined levels.
Claim 4
Dependent Claim
21 words
Apparatus in accordance with claim 1 in which said antenna assembly includes dielectric means conformable to said surface of said earth.
Claim 5
Dependent Claim
30 words
Apparatus in accordance with claim 3 in which said feedback control means is further connected to said receiver to protect said receiver during periods when received signals exceed predetermined levels.
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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) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |