Patent US3735404A successfully refreshed from Google Patents.
US3735404A
Expired / Lapsed
US
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Crossover circuit for monopulse radar
Assignee: United States Department of the Air Force
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Filing: 1965-06-07
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Granted: 1973-05-22
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Expires: 1985-06-07
Abstract
Abstract 2. Apparatus as claimed in claim 1 in which said radar system comprises in addition means for generating a range gate following each radiated pulse and in which said crossover circuit comprises in addition means connected to the last name detector, controlled by said range gate and operative during said range gate to increase said detector threshold from a preset initial value as a direct approximately linear function of range.
Inventors
- 👤 E Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:56
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/06; G01S13/42; G01S13/44; G01S13/4445; G01S13/88; G01S13/93; G01S13/933; G01S13/935
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
227 words
A crossover circuit for a terrain following monopulse radar system of the type in which pulses of high frequency energy are radiated by a directional antenna toward the terrain and in which there are produced from the energy reflected from the area of the terrain illuminated by the radiated energy a sum video signal having a maximum value at the range at which the boresight line of said antenna intersects the terrain and a difference video signal that is zero at said range and has portions of opposite polarities on either side thereof, said crossover circuit comprising: means for applying said difference signal to first and second channels in parallel; said first channel containing means for detecting and inverting the positive portion of said difference signal; said second channel containing means for inverting said difference signal, means for delaying the inverted signal by an amount approximately equal to the duration of said radiated pulses and means for detecting and inverting the positive portion of the delayed inverted difference signal; means for adding said sum signal to the outputs of said first and second channels; a detector having a preset threshold; and means for applying the signal resulting from said addition to the last named detector, whereby a detector output is produced whenever the applied signal exceeds said threshold, said output constituting the output of said crossover circuit.
Claim 2
Dependent Claim
227 words
A crossover circuit for a terrain following monopulse radar system of the type in which pulses of high frequency energy are radiated by a directional antenna toward the terrain and in which there are produced from the energy reflected from the area of the terrain illuminated by the radiated energy a sum video signal having a maximum value at the range at which the boresight line of said antenna intersects the terrain and a difference video signal that is zero at said range and has portions of opposite polarities on either side thereof, said crossover circuit comprising: means for applying said difference signal to first and second channels in parallel; said first channel containing means for detecting and inverting the positive portion of said difference signal; said second channel containing means for inverting said difference signal, means for delaying the inverted signal by an amount approximately equal to the duration of said radiated pulses and means for detecting and inverting the positive portion of the delayed inverted difference signal; means for adding said sum signal to the outputs of said first and second channels; a detector having a preset threshold; and means for applying the signal resulting from said addition to the last named detector, whereby a detector output is produced whenever the applied signal exceeds said threshold, said output constituting the output of said crossover circuit.
Claim 3
Dependent Claim
227 words
A crossover circuit for a terrain following monopulse radar system of the type in which pulses of high frequency energy are radiated by a directional antenna toward the terrain and in which there are produced from the energy reflected from the area of the terrain illuminated by the radiated energy a sum video signal having a maximum value at the range at which the boresight line of said antenna intersects the terrain and a difference video signal that is zero at said range and has portions of opposite polarities on either side thereof, said crossover circuit comprising: means for applying said difference signal to first and second channels in parallel; said first channel containing means for detecting and inverting the positive portion of said difference signal; said second channel containing means for inverting said difference signal, means for delaying the inverted signal by an amount approximately equal to the duration of said radiated pulses and means for detecting and inverting the positive portion of the delayed inverted difference signal; means for adding said sum signal to the outputs of said first and second channels; a detector having a preset threshold; and means for applying the signal resulting from said addition to the last named detector, whereby a detector output is produced whenever the applied signal exceeds said threshold, said output constituting the output of said crossover circuit.
Claim 4
Dependent Claim
227 words
A crossover circuit for a terrain following monopulse radar system of the type in which pulses of high frequency energy are radiated by a directional antenna toward the terrain and in which there are produced from the energy reflected from the area of the terrain illuminated by the radiated energy a sum video signal having a maximum value at the range at which the boresight line of said antenna intersects the terrain and a difference video signal that is zero at said range and has portions of opposite polarities on either side thereof, said crossover circuit comprising: means for applying said difference signal to first and second channels in parallel; said first channel containing means for detecting and inverting the positive portion of said difference signal; said second channel containing means for inverting said difference signal, means for delaying the inverted signal by an amount approximately equal to the duration of said radiated pulses and means for detecting and inverting the positive portion of the delayed inverted difference signal; means for adding said sum signal to the outputs of said first and second channels; a detector having a preset threshold; and means for applying the signal resulting from said addition to the last named detector, whereby a detector output is produced whenever the applied signal exceeds said threshold, said output constituting the output of said crossover circuit.
References Cited (Backward Citations)
US3427616A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |