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US3754252A
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Adaptive array retrodirective landing control responser
Assignee: TDK Micronas GmbH
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Filing: 1971-10-06
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Granted: 1973-08-21
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Expires: 1991-10-06
Abstract
Abstract A landing control system normally quiescent but responsive to pulsed interrogation from an aircraft to be given (typically) elevation and azimuth angle information for landing approach. The ground responser equipment determines the angle of arrival of the interrogation pulses through an adaptive phased array arrangement and retransmits that information as a coded reply. Range information is air derived through the measurement of time delay in receiving the coded responser reply corresponding to each interrogation.
Inventors
- 👤 L Sanders
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:58
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; G01S13/76; G01S13/765; G01S13/88; G01S13/91; G01S13/913
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
170 words
A radar responser system for determining, at a first station, at least a first angular coordinate of a second station and transmitting reply signals representative of said angular coordinate from said first station to said second station in response to interrogation pulses from said second station, comprising: an antenna array located at said first station for receiving said interrogation pulses, said array including a plurality of separately excited antenna elements arranged to form a beam narrow in said first angular coordinate; means for generating a phase comparison signal discretely for each of said antenna elements, as a function of the angle of reception at said array of said interrogation pulses; phase control means responsive to said phase comparison signal to control the feed phase of each of said antenna elements independently to form said beam at said first angular coordinate; and means responsive to said phase comparison signal for transmitting a reply signal from said first station to said second station, said reply signal being representative of said angle coordinate.
Claim 2
Dependent Claim
170 words
A radar responser system for determining, at a first station, at least a first angular coordinate of a second station and transmitting reply signals representative of said angular coordinate from said first station to said second station in response to interrogation pulses from said second station, comprising: an antenna array located at said first station for receiving said interrogation pulses, said array including a plurality of separately excited antenna elements arranged to form a beam narrow in said first angular coordinate; means for generating a phase comparison signal discretely for each of said antenna elements, as a function of the angle of reception at said array of said interrogation pulses; phase control means responsive to said phase comparison signal to control the feed phase of each of said antenna elements independently to form said beam at said first angular coordinate; and means responsive to said phase comparison signal for transmitting a reply signal from said first station to said second station, said reply signal being representative of said angle coordinate.
Claim 3
Dependent Claim
108 words
The invention set forth in claim 1 in which said phase control means includes a plurality of phase shifters each having a first terminal connected to a corresponding one of said antenna elements, and including a stable reference frequency source having a frequency fixed with respect to the frequency of said interrogation pulses, and in which said phase comparison means includes a phase detector connected to compare the phase of the output of said reference source with the phase of energy at the second terminal of each of said phase shifters to produce and apply a corresponding phase sHifter control signal to control input of each phase shifter.
Claim 4
Dependent Claim
31 words
Apparatus according to claim 2 in which said first and second phase shifter terminals are defined as the radio frequency terminals thereof, and said phase shifter is of a reciprocal type.
Claim 5
Dependent Claim
49 words
Apparatus according to claim 3 including correlator means responsive to at least some of the plurality of said phase shifter control signals for generating a beam angle representing signal, and transmitter means for transmitting said beam angle representing signal in response to each interrogation pulse from said second station.
Claim 6
Dependent Claim
88 words
Apparatus according to claim 4 in which said second station comprises a source of radio frequency interrogation pulses, a second station antenna for transmitting said interrogation pulses, second station receiver means for decoding said reply signals from said first station to produce an angle indicating signal at said second station, and second station duplexing means interconnecting said second station antenna, said source of interrogation pulses and said second station receiver, whereby said second station receiver means is operative at times other than during transmission of said interrogation pulses.
Claim 7
Dependent Claim
55 words
Apparatus according to claim 5 in which said second station also includes range tracking means responsive to the output of said second station receiver and said source of interrogation pulses for determining range to said first station as a function of time elapsed between said interrogation pulses and corresponding reply signals from said first station.
Claim 8
Dependent Claim
54 words
Apparatus according to claim 4 in which said means for transmitting said beam angle representing signal at said first station includes receiving means responsive to said interrogation pulses received at said array for producing contemporaneous corresponding synchronizing pulses, and including a coder responsive to said synchronizing pulses and the output of said correlator means.
Claim 9
Dependent Claim
53 words
Apparatus according to claim 7 including a duplexer corresponding to each of said antenna elements, said duplexer interconnecting said phase shifter second terminal with said receiver and said phase detector during reception of said interrogating signals and interconnecting said phase shifter second terminal with said transmitter means during generation of said reply signals.
Claim 10
Dependent Claim
57 words
Apparatus according to claim 3 in which each of said phase shifters and its corresponding phase detector comprises a servo loop for adapting the value of phase shift in each of said phase shifters as a function of the angle of reception of said interrogating pulses and the position of the corresponding antenna element along said array.
Claim 11
Dependent Claim
57 words
Apparatus according to claim 8 in which said correlator means comprises a digital read only device which produces a digital code representative of said angular coordinate from stored values in response to input signals consisting of a said phase comparison signals, and said coder passed said digital code for transmission contemporaneously with occurrence of said synchronizing pulses.
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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) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |