Patent US2695803A successfully refreshed from Google Patents.
Patent US3794995A successfully refreshed from Google Patents.
US3794995A
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Modulation signal generator and apparatus using such generator
Assignee: Raytheon Co
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Filing: 1972-08-02
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Granted: 1974-02-26
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Expires: 1992-08-02
Abstract
Abstract Improved apparatus for generating a time-varying analog signal, as for example, a chirp modulation signal for a pulse compression radar, is shown. The disclosed apparatus incorporates: a memory for storing a set of digital words representative of samples of the time-varying analog signal; at least two digital-to-analog converters having their outputs connected to a common bus; and means for distributing, at a predetermined rate, successively read digital words from the memory to the digital-to-analog converters. Each one of the latter elements is actuated also by a time-varying weighting signal so the frequency spectrum of the desired time-varying analog signal is within predetermined limits.
Inventors
- 👤 B Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:04
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/06; G01S13/08; G01S13/10; G01S13/26; G01S13/28; G01S13/282; H; H03; H03C; H03C1/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
149 words
In a pulse radar system periodically transmitting a coded modulation signal, such modulation signal being generated by conversion of a set of digital words stored in a memory, improved conversion apparatus comprising: a. means for periodically reading the set of digital words out of the memory at a first rate and dividing such set into equal interlaced subsets of digital words; b. a number, corresponding to the number of subsets of digital words, of digital-to-analog converters, each one thereof being responsive to a different one of the equal interleaved sets of digital words to produce a different analog signal at a second rate lower than the first rate; c. weighting means for applying a different time-varying signal at the second rate to each one of the diGital-to-analog converters to weight each different analog signal; and d. means for combining each different analog signal to produce the coded modulation signal.
Claim 2
Dependent Claim
149 words
In a pulse radar system periodically transmitting a coded modulation signal, such modulation signal being generated by conversion of a set of digital words stored in a memory, improved conversion apparatus comprising: a. means for periodically reading the set of digital words out of the memory at a first rate and dividing such set into equal interlaced subsets of digital words; b. a number, corresponding to the number of subsets of digital words, of digital-to-analog converters, each one thereof being responsive to a different one of the equal interleaved sets of digital words to produce a different analog signal at a second rate lower than the first rate; c. weighting means for applying a different time-varying signal at the second rate to each one of the diGital-to-analog converters to weight each different analog signal; and d. means for combining each different analog signal to produce the coded modulation signal.
Claim 3
Dependent Claim
77 words
Improved conversion apparatus as in claim 1 wherein the first-named means includes: a. a clock pulse generator producing clock pulses at a first rate; and, b. means for periodically dividing the clock pulses into a number, corresponding to the number of digital-to-analog converters, of equal interlaced subsets of clock pulses and applying such subsets of clock pulses to the memory to actuate each one of the digital-to-analog converters at a second rate, lower than the first rate.
Claim 4
Dependent Claim
76 words
Improved conversion apparatus as in claim 2 wherein the weighting means includes: a. a source of DC voltage; b. a number of oscillator means corresponding in number to the number of D/A converters, each one of such means being synchronized by a different one of the equal interlaced subsets of clock pulses, for producing cosinusoidal signals having different relative phases; and c. summing means to combine the DC voltage and each one of the cosinusoidal signals.
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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) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |