US3745559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Analog to digital converter
Assignee: Westinghouse Electric Corp
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Filing: 1972-06-01
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Granted: 1973-07-10
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Expires: 1992-06-01
Abstract
Abstract Apparatus for directly generating a cyclical multi-bit Gray code digital output by means of a plurality of identical cascaded frequency multiplier stages, each of which includes a frequency doubler, a mixer, a phase detector and a squaring amplifier, wherein the output of each frequency doubler is translated to its input frequency and phase detected against a reference carrier signal. The output of each stage when limited, provides a digitized output bit in a Gray code format.
Inventors
- 👤 J Mattern
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:05
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/06; H03M1/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
216 words
Analog to digital conversion apparatus comprising, in combination: means for providing a first and second refernece signal of the same carrier frequency; input means for receiving an analog input signal; a phase modulator coupled to said analog input signal and said first reference signal whereby said modulator shifts the phase of said first reference signal as a function of the analog input signal and provides an output signal in accordance therewith; a plurality of N identical cascaded conversion stages providing N digital output bits respectively in a Gray code format, each stage including, a frequency multiplier, a dual input frequency mixer having one input coupled to the output of said frequency multiplier circuit, a dual input phase detector having one input coupled to the output of said mixer, and a squaring amplifier coupled to the output of the phase detector for providing a digital output bit; circuit means coupling the output of said phase modulator to the input of the frequency multiplier of the first stage; circuit means coupling the output of all the mixers respectively to the input of the succeeding frequency multiplier; circuit means coupling said second reference signal to the other input of all said mixers; and circuit means coupling said first reference signal to the other input of all said phase detectors.
Claim 2
Dependent Claim
216 words
Analog to digital conversion apparatus comprising, in combination: means for providing a first and second refernece signal of the same carrier frequency; input means for receiving an analog input signal; a phase modulator coupled to said analog input signal and said first reference signal whereby said modulator shifts the phase of said first reference signal as a function of the analog input signal and provides an output signal in accordance therewith; a plurality of N identical cascaded conversion stages providing N digital output bits respectively in a Gray code format, each stage including, a frequency multiplier, a dual input frequency mixer having one input coupled to the output of said frequency multiplier circuit, a dual input phase detector having one input coupled to the output of said mixer, and a squaring amplifier coupled to the output of the phase detector for providing a digital output bit; circuit means coupling the output of said phase modulator to the input of the frequency multiplier of the first stage; circuit means coupling the output of all the mixers respectively to the input of the succeeding frequency multiplier; circuit means coupling said second reference signal to the other input of all said mixers; and circuit means coupling said first reference signal to the other input of all said phase detectors.
Claim 3
Dependent Claim
31 words
The apparatus as defined by claim 1 wherein said frequency multiplier circuits of all said N conversion stages multiply the frequency of the respective input signal by a factor of 2.
Claim 4
Dependent Claim
61 words
The apparatus as defined by claim 2 and additionally including a sign bit conversion stage comprising another dual input phase detector circuit having one input coupled to the output signal of said phase modulator and the other input to said second reference signal, and a squaring amplifier coupled to the output of said phase detector for providing a digital signal output.
Claim 5
Dependent Claim
23 words
The apparatus as defined by claim 3 wherein said means for providing a first and second reference signal comprises a sine wave oscillator.
Claim 6
Dependent Claim
15 words
The apparatus as defined by claim 4 wherein said oscillator comprises a microwave signal generator.
Claim 7
Dependent Claim
17 words
The apparatus as defined by claim 1 wherein said input means comprises a sample and hold circuit.
Claim 8
Dependent Claim
36 words
The apparatus as defined by claim 3 wherein said squaring amplifiers of said N identical conversion stages include signal inversion means and wherein said squaring amplifier in said sign bit conversion stage comprises non-inverting signal means.
Claim 9
Dependent Claim
37 words
The apparatus as defined by claim 1 wherein said phase modulator is adapted to phase modulate said first reference signal between the limits of +90* and -90* in accordance with the magnitude of said analog input signal.
Claim 10
Dependent Claim
25 words
The apparatus as defined by claim 1 wherein said first and second reference signals comprise the signals sin omega t and cos omega t, respectively.
Claim 11
Dependent Claim
23 words
The apparatus as defined by claim 9 wherein omega 2 pi f and wherein f is a carrier frequency in the microwave range.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |