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US3754251A
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Anti-synchronous reply circuit
Assignee: Ltv Electrosystems Inc
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Filing: 1972-01-17
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Granted: 1973-08-21
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Expires: 1992-01-17
Abstract
Abstract In radio navigation systems located in areas that are rich with interrogation reflections a variable dead time provides smearing of replies during the interrogation time window generated by the interrogation reflections. A radio navigation system of the type described receives a pair of interrogation pulses which are decoded into a single pulse for operation of a reply transmitter. The interrogation pulse receiver decodes the interrogation pulses only during the active time span thereof and when received interrogation pulses are spaced over the required time span. The transmitter generates position determining signals in response to the decoded interrogation pulses. To block-out or smear the position determining signals emitting from the transmitter generated by interrogation pulse reflections, a variable width blanking pulse is generated for deactivating the interrogation pulse receiver. This variable width blanking pulse is generated in an anti-synchronous circuit responsive to the decoded interrogation pulses and timed clock pulses.
Inventors
- 👤 D Thornberg
- 👤 A Capes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:25
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; G01S13/76; G01S13/78; G01S13/781; G01S13/784; G01S13/762
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
110 words
An anti-synchronous reply circuit in a radio navigation system wherein coded interrogation pulses actuate circuitry for producing a reply signal, comprising: means responsive to a decoded interrogation pulse received by the navigation system for generating a fixed time width pulse, a bi-stable circuit responsive to the fixed time width pulse and triggered thereby into a second of two stable conditions, and circuit means connected to said bi-stable circuit and responsive to the fixed time width pulse and a series of timed clock pulses for returning said bi-stable circuit to a first stable condition upon the occurrence of a timed clock pulse after the termination of the fixed time width pulse.
Claim 2
Dependent Claim
110 words
An anti-synchronous reply circuit in a radio navigation system wherein coded interrogation pulses actuate circuitry for producing a reply signal, comprising: means responsive to a decoded interrogation pulse received by the navigation system for generating a fixed time width pulse, a bi-stable circuit responsive to the fixed time width pulse and triggered thereby into a second of two stable conditions, and circuit means connected to said bi-stable circuit and responsive to the fixed time width pulse and a series of timed clock pulses for returning said bi-stable circuit to a first stable condition upon the occurrence of a timed clock pulse after the termination of the fixed time width pulse.
Claim 3
Dependent Claim
30 words
An anti-synchronous reply circuit in a radio navigation system as set forth in claim 1 including clock means for generating a series of timed clock pulses to said circuit means.
Claim 4
Dependent Claim
36 words
An anti-synchronous reply circuit in a radio navigation system as set forth in claim 1 wherein said means responsive to a decoded interrogation pulse includes a one shot multi-vibrator generating a fixed time width output pulse.
Claim 5
Dependent Claim
43 words
An anti-synchronous reply circuit in a radio navigation system as set forth in claim 1 wherein said bi-stable circuit includes a flip-flop having a ''''set'''' input terminal responsive to the fixed time width pulses and a ''''clear'''' terminal connected to said circuit means.
Claim 6
Dependent Claim
142 words
A radio navigation system including a navigation receiver for decoding interrogation pulses and a transmitter responsive to the decoded pulses, comprising: a one-shot multi-vibrator responsive to the decoded interrogation pulse for generating a fixed time width output pulse, a flip-flop having a ''''set'''' terminal responsive to the fixed time width output pulse of said one-shot multi-vibrator for generating a blanking pulse to disable the navigation receiver from decoding received interrogation pulses, and circuit means connected to a clear input terminal of said flip-flop and responsive to the fixed time width pulse of said one-shot multi-vibrator along with a series of timed clock pulses for returning said flip-flop to a first of two stable conditions upon the first occurrence of a timed clock pulse after termination of the fixed time width output pulse of said one-shot multi-vibrator to vary the blanking pulse width.
Claim 7
Dependent Claim
142 words
A radio navigation system including a navigation receiver for decoding interrogation pulses and a transmitter responsive to the decoded pulses, comprising: a one-shot multi-vibrator responsive to the decoded interrogation pulse for generating a fixed time width output pulse, a flip-flop having a ''''set'''' terminal responsive to the fixed time width output pulse of said one-shot multi-vibrator for generating a blanking pulse to disable the navigation receiver from decoding received interrogation pulses, and circuit means connected to a clear input terminal of said flip-flop and responsive to the fixed time width pulse of said one-shot multi-vibrator along with a series of timed clock pulses for returning said flip-flop to a first of two stable conditions upon the first occurrence of a timed clock pulse after termination of the fixed time width output pulse of said one-shot multi-vibrator to vary the blanking pulse width.
Claim 8
Dependent Claim
26 words
A radio navigation system as set forth in claim 5 including clock means for generating a series of timed clock pulses connected to said circuit means.
Claim 9
Dependent Claim
50 words
A radio navigation system as set forth in claim 6 wherein said circuit means includes a NAND gate having one input connected to receive the series of timed clock pulses from said clock means and a second input connected to the fixed time width output pulse from said one-shot multi-vibrator.
Claim 10
Dependent Claim
115 words
A radio navigation system including a navigation receiver for decoding interrogation pulses and a transmitter responsive to the decoded pulses, comprising in combination: first means responsive to an input pulse for generating a fixed time width pulse, output means for generating a first output signal to enable the navigation receiver and a blanking pulse to disable the navigation receiver from decoding the interrogation pulses, clock means for generating a series of timed clock pulses, and circuit means responsive to the fixed time width pulses and the timed clock pulses for returning said output means to the first output signal upon the occurrence of a timed clock pulse after termination of the fixed time width pulse.
Claim 11
Dependent Claim
115 words
A radio navigation system including a navigation receiver for decoding interrogation pulses and a transmitter responsive to the decoded pulses, comprising in combination: first means responsive to an input pulse for generating a fixed time width pulse, output means for generating a first output signal to enable the navigation receiver and a blanking pulse to disable the navigation receiver from decoding the interrogation pulses, clock means for generating a series of timed clock pulses, and circuit means responsive to the fixed time width pulses and the timed clock pulses for returning said output means to the first output signal upon the occurrence of a timed clock pulse after termination of the fixed time width pulse.
Claim 12
Dependent Claim
32 words
A radio navigation system as set forth in claim 8 including input means responsive to any one of a plurality of control signals for generating the input pulse to said first means.
Claim 13
Dependent Claim
100 words
An anti-synchronous reply circuit in a radio navigation system, comprising in combination: means responsive to any one of a plurality of input pulses for generating a fixed time width pulse, a bistable circuit responsive to the fixed time width pulse and triggered thereby into a second of two stable conditions, and circuit means connected to said bistable circuit and responsive to the fixed time width pulse and a series of timed clock pulses for returning said bistable circuit to a first stable condition upon the occurrence of a timed clock pulse after the termination of the fixed time width pulse.
Claim 14
Dependent Claim
100 words
An anti-synchronous reply circuit in a radio navigation system, comprising in combination: means responsive to any one of a plurality of input pulses for generating a fixed time width pulse, a bistable circuit responsive to the fixed time width pulse and triggered thereby into a second of two stable conditions, and circuit means connected to said bistable circuit and responsive to the fixed time width pulse and a series of timed clock pulses for returning said bistable circuit to a first stable condition upon the occurrence of a timed clock pulse after the termination of the fixed time width pulse.
Claim 15
Dependent Claim
52 words
An anti-synchronous reply circuit as set forth in claim 10 wherein said means responsive to a plurality of input pulses includes a one-shot multi-vibrator generating the fixed time width output pulse, and means responsive to any one of the plurality of input signals for generating a trigger pulse to said one-shot multi-vibrator.
References Cited (Backward Citations)
US3646556A
Cited
US3680090A
Cited
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 |