US4482957A
Expired / Lapsed
US
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Use of a square root amplifier for statistics limited data
Assignee: American Science and Engineering Inc
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Filing: 1981-11-04
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Granted: 1984-11-13
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Expires: 2001-11-04
Abstract
Abstract An analog signal having a quantum noise component undergoes conversion by a square root amplifier. The converted signal then undergoes analog-to-digital conversion resulting in a digital output wherein a single bit change always represents a constant fraction of a standard deviation, independent of signal intensity. Thus, a single unit of the quantum noise component may be stored as a single bit of a data word.
Inventors
- 👤 Paul J. Bjorkholm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:21
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/17; H; H04; H04N; H04N23/00; H04N23/30
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
104 words
A method for minimizing the data storage requirement of a detected quantum noise limited signal comprising the steps: detecting the photons of an analog quantum limited signal wherein the standard deviation thereof is proportional to the square root of the number of detected photons; subjecting the detected signal to square root amplification; performing an analog-to-digital conversion on the signal after the amplification for transforming the magnitude of quantum noise fluctuations to a constant voltage value, independent of signal attenuation; and storing the converted signal; wherein a single bit change of stored data represents a constant fraction of a standard deviation independent of signal intensity.
Claim 2
Independent Claim
104 words
A method for minimizing the data storage requirement of a detected quantum noise limited signal comprising the steps: detecting the photons of an analog quantum limited signal wherein the standard deviation thereof is proportional to the square root of the number of detected photons; subjecting the detected signal to square root amplification; performing an analog-to-digital conversion on the signal after the amplification for transforming the magnitude of quantum noise fluctuations to a constant voltage value, independent of signal attenuation; and storing the converted signal; wherein a single bit change of stored data represents a constant fraction of a standard deviation independent of signal intensity.
Claim 3
Independent Claim
120 words
A method for minimizing the data storage requirement of an X-ray signal comprising the steps: generating an X-ray beam; detecting photons of said beam after passage through an object resulting in an X-ray signal characterized as an analog quantum limited signal wherein the standard deviation thereof is proportional to the square root of the number of detected photons; subjecting the signal to square root amplification; performing an analog-to-digital conversion on the signal after the amplification for transforming the magnitude of quantum noise fluctuations to a constant voltage value, independent of signal attenuation; and storing the converted signal as a binary data word wherein a single bit change always represents a constant fraction of a standard deviation independent of signal intensity.
Claim 4
Independent Claim
120 words
A method for minimizing the data storage requirement of an X-ray signal comprising the steps: generating an X-ray beam; detecting photons of said beam after passage through an object resulting in an X-ray signal characterized as an analog quantum limited signal wherein the standard deviation thereof is proportional to the square root of the number of detected photons; subjecting the signal to square root amplification; performing an analog-to-digital conversion on the signal after the amplification for transforming the magnitude of quantum noise fluctuations to a constant voltage value, independent of signal attenuation; and storing the converted signal as a binary data word wherein a single bit change always represents a constant fraction of a standard deviation independent of signal intensity.
Claim 5
Dependent Claim
118 words
A circuit for converting quantum limited signals to minimized digital data, the circuit comprising: means for detecting the photons of an analog quantum limited signal wherein the standard deviation thereof is proportional to the square root of the number of detected photons; square root amplifying means connected at the input thereof to the output of the detecting means; and analog-to-digital converting means connected at the input thereof to the output of the amplifying means for transforming the magnitude of quantum noise fluctuations to a constant voltage value independent of signal attenuation; and means for storing the converted signal; wherein a single bit change of stored data represents a constant fraction of a standard deviation, independent of signal intensity.
Claim 6
Dependent Claim
118 words
A circuit for converting quantum limited signals to minimized digital data, the circuit comprising: means for detecting the photons of an analog quantum limited signal wherein the standard deviation thereof is proportional to the square root of the number of detected photons; square root amplifying means connected at the input thereof to the output of the detecting means; and analog-to-digital converting means connected at the input thereof to the output of the amplifying means for transforming the magnitude of quantum noise fluctuations to a constant voltage value independent of signal attenuation; and means for storing the converted signal; wherein a single bit change of stored data represents a constant fraction of a standard deviation, independent of signal intensity.
Claim 7
Dependent Claim
43 words
The structure of claim 3 wherein the square root amplifying means comprises: a logarithmic amplifier; means for dividing an output from the logarithmic amplifier by a preselected constant; and an anti-logarithmic amplifier having its input connected to an output of the dividing means.
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) | 1987-11-13 | 1988-05-14 | 1988-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-13 | 1992-05-14 | 1992-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-13 | 1996-05-14 | 1996-11-13 | $7700.00 | Window Closed / Lapsed |