US3721906A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coded pulse pair detector with improved detection probability
Assignee: International Standard Electric Corp
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Filing: 1970-06-15
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Granted: 1973-03-20
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Expires: 1990-06-15
Abstract
Abstract An improved decoder for IFF interrogations is provided to increase the average probability of detection. The first pulse of the pulse pair interrogation is stretched via logic circuitry to increase the probability of coincidence with the second pulse of the interrogation. This allows for a certain amount of variation or jitter in the timing of the incoming pulse pair.
Inventors
- 👤 M Geesen
- 👤 A Laganier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:54
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/74; G01S13/76; G01S13/78; G01S13/781; G01S13/784
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
182 words
A system for recognition of an incoming pulse code group including at least a pair of pulses nominally spaced by To, but subject to extraneous variations thereabout, said system including means for generating periodic clock pulses, an input for receiving said incoming pulse group, a shift register responsive at a signal input to said incoming pulse code group and at a control input to said clock pulses for advancing the pulses received at said signal input one register section for each clock pulse, comprising: a set of coincidence detectors each having an input connected to receive said incoming pulse code group; means for applying the first pulse of each incoming pair q successive times to the input of said register; and means for recognizing said pair at an output S comprising a predetermined tap along said register, wherein S is equal to n - (a/2) when q is an even number, and S is equal to n - (q 1)/2 when q is an odd number, S being equal to the interval To divided by the period theta of said clock pulses.
Claim 2
Independent Claim
182 words
A system for recognition of an incoming pulse code group including at least a pair of pulses nominally spaced by To, but subject to extraneous variations thereabout, said system including means for generating periodic clock pulses, an input for receiving said incoming pulse group, a shift register responsive at a signal input to said incoming pulse code group and at a control input to said clock pulses for advancing the pulses received at said signal input one register section for each clock pulse, comprising: a set of coincidence detectors each having an input connected to receive said incoming pulse code group; means for applying the first pulse of each incoming pair q successive times to the input of said register; and means for recognizing said pair at an output S comprising a predetermined tap along said register, wherein S is equal to n - (a/2) when q is an even number, and S is equal to n - (q 1)/2 when q is an odd number, S being equal to the interval To divided by the period theta of said clock pulses.
Claim 3
Independent Claim
140 words
A system for recognition of pairs of incoming pulses spaced apart by an interval of time T, said interval being variable about a nominal value To, said system comprising: means for producing periodic timing pulses; an input for receiving said incoming pulses; a shift register synchronized by said timing pulses and responsive to record said incoming pulse; a set of coincidence detectors, each of said detectors being connected to said input; means for applying the first incoming pulse of each pair q successive times to the input of said register; and means for recognizing said pair at an output tap S along said register, S being equal to n - (q/2) when q is an even number and S being equal to n - (q-1)/2 when q is an odd number, n being equal to To/ theta + 1/2 .
Claim 4
Independent Claim
140 words
A system for recognition of pairs of incoming pulses spaced apart by an interval of time T, said interval being variable about a nominal value To, said system comprising: means for producing periodic timing pulses; an input for receiving said incoming pulses; a shift register synchronized by said timing pulses and responsive to record said incoming pulse; a set of coincidence detectors, each of said detectors being connected to said input; means for applying the first incoming pulse of each pair q successive times to the input of said register; and means for recognizing said pair at an output tap S along said register, S being equal to n - (q/2) when q is an even number and S being equal to n - (q-1)/2 when q is an odd number, n being equal to To/ theta + 1/2 .
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) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |