US4958308A
Expired / Lapsed
US
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Technique for improving the resolution of an A/D converter
Assignee: Varian Australia Pty Ltd
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Filing: 1988-10-21
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Granted: 1990-09-18
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Expires: 2008-10-21
Abstract
Abstract The present invention provides a technique for improving the resolution of an A/D converter. The input analog signal is sampled to generate an analog level and the analog level is held for an interval. A random noise signal having zero average value is superimposed on the held level to generate a fluctuating voltage. This fluctuating voltage is then sampled a plurality of at least N times, and N sampled values are communicated to the A/D converter so that N digitized values are generated. These digitized values are averaged to provide an output having a digitization error reduced by a factor of N 1/2 .
Inventors
- 👤 Raul Curbelo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:35
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/12; H03M1/20; H03M1/201
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
138 words
A method of digitizing the output signal from a Fourier transform spectrometer, comprising the steps of: communicating an analog voltage level representing the output signal to a summing node; superimposing random noise fluctuations having an average value of zero on the analog voltage level at the summing node to provide a fluctuating voltage signal centered at the analog voltage level and having a duration of at least a predetermined time interval; sampling the fluctuating voltage signal a plurality of N times during the tim interval to provide a plurality of N voltages; communicating the N voltages, one at a time, to the input of an A/D converter having a given resolution to provide N digitized values; and averaging the N digitized values to provide an output with a digitization error reduced by a factor of N 1/2 .
Claim 2
Independent Claim
138 words
A method of digitizing the output signal from a Fourier transform spectrometer, comprising the steps of: communicating an analog voltage level representing the output signal to a summing node; superimposing random noise fluctuations having an average value of zero on the analog voltage level at the summing node to provide a fluctuating voltage signal centered at the analog voltage level and having a duration of at least a predetermined time interval; sampling the fluctuating voltage signal a plurality of N times during the tim interval to provide a plurality of N voltages; communicating the N voltages, one at a time, to the input of an A/D converter having a given resolution to provide N digitized values; and averaging the N digitized values to provide an output with a digitization error reduced by a factor of N 1/2 .
Claim 3
Independent Claim
159 words
A method of digitizing the output signal from a Fourier transform spectrometer, comprising the steps of: sampling the spectrometer output signal to generate an analog voltage level whose value equals the value of the spectrometer output signal at the moment of sampling; holding the analog voltage level for at least a predetermined time interval; superimposing random noise fluctuations having an average value of zero on the analog voltage level to provide a fluctuating voltage signal centered at the analog voltage level and having a duration of at least the predetermined time interval; sampling the fluctuating voltage signal a plurality of N times during the time interval to provide a plurality of N voltages; communicating the N voltages, one at a time, to the input of an A/D converter having a given resolution to provide N digitized values; and averaging the N digitized values to provide an output with a digitization error reduced by a factor of N 1/2 .
Claim 4
Independent Claim
159 words
A method of digitizing the output signal from a Fourier transform spectrometer, comprising the steps of: sampling the spectrometer output signal to generate an analog voltage level whose value equals the value of the spectrometer output signal at the moment of sampling; holding the analog voltage level for at least a predetermined time interval; superimposing random noise fluctuations having an average value of zero on the analog voltage level to provide a fluctuating voltage signal centered at the analog voltage level and having a duration of at least the predetermined time interval; sampling the fluctuating voltage signal a plurality of N times during the time interval to provide a plurality of N voltages; communicating the N voltages, one at a time, to the input of an A/D converter having a given resolution to provide N digitized values; and averaging the N digitized values to provide an output with a digitization error reduced by a factor of N 1/2 .
Claim 5
Dependent Claim
19 words
The method of claim 2 wherein all of said steps are performed a plurality of times in repeated sequences.
Claim 6
Dependent Claim
127 words
Apparatus for digitizing the output signal from a Fourier transform spectrometer, comprising: means for superimposing random noise fluctuations having an average value of zero on an analog voltage level representing the output signal to provide a fluctuating voltage signal centered at the analog voltage level and having a duration of at least a predetermined time interval; sample and hold means for providing N analog voltage levels corresponding to N values of said fluctuating voltage signal occurring during the time interval; an A/D converter having a given resolution; means for communicating said N analog voltage levels to said A/D converter for providing N digitized values; and means for coadding the N digitized values to provide an average value having increased resolution by a factor of N 1/2 .
Claim 7
Dependent Claim
127 words
Apparatus for digitizing the output signal from a Fourier transform spectrometer, comprising: means for superimposing random noise fluctuations having an average value of zero on an analog voltage level representing the output signal to provide a fluctuating voltage signal centered at the analog voltage level and having a duration of at least a predetermined time interval; sample and hold means for providing N analog voltage levels corresponding to N values of said fluctuating voltage signal occurring during the time interval; an A/D converter having a given resolution; means for communicating said N analog voltage levels to said A/D converter for providing N digitized values; and means for coadding the N digitized values to provide an average value having increased resolution by a factor of N 1/2 .
Claim 8
Dependent Claim
26 words
The apparatus of claim 4 wherein said A/D converter has a particular digitization increment, and said fluctuating voltage has maximum fluctuations that exceed the digitization increment.
Claim 9
Dependent Claim
163 words
Apparatus for digitizing the output signal from a Fourier transform spectrometer, comprising: first sample and hold means, responsive to the spectrometer output signal, for providing an analog voltage level whose value equals the value of the spectrometer output signal at a particular moment; means for superimposing random noise fluctuations having an average value of zero on said analog voltage level from said first sample and hold means to provide a fluctuating voltage signal centered at said analog voltage level and having a duration of at least a predetermined time interval. second sample and hold means for providing N analog voltage levels corresponding to N values of said fluctuating voltage signal occurring during the tim e interval; an A/D converter having a given resolution; means for communicating said N analog voltage levels to said A/D converter for providing N digitized values; and means for coadding the N digitized values to provide and average value having increased resolution by a factor of N 1/2 .
Claim 10
Dependent Claim
163 words
Apparatus for digitizing the output signal from a Fourier transform spectrometer, comprising: first sample and hold means, responsive to the spectrometer output signal, for providing an analog voltage level whose value equals the value of the spectrometer output signal at a particular moment; means for superimposing random noise fluctuations having an average value of zero on said analog voltage level from said first sample and hold means to provide a fluctuating voltage signal centered at said analog voltage level and having a duration of at least a predetermined time interval. second sample and hold means for providing N analog voltage levels corresponding to N values of said fluctuating voltage signal occurring during the tim e interval; an A/D converter having a given resolution; means for communicating said N analog voltage levels to said A/D converter for providing N digitized values; and means for coadding the N digitized values to provide and average value having increased resolution by a factor of N 1/2 .
Claim 11
Dependent Claim
26 words
The apparatus of claim 6 wherein said A/D converter has a particular digitization increment, and said fluctuating voltage has maximum fluctuations that exceed the digitization increment.
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) | 1993-09-17 | 1994-03-19 | 1994-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-17 | 1998-03-19 | 1998-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-17 | 2002-03-19 | 2002-09-18 | $7700.00 | Window Closed / Lapsed |