US4802098A
Expired / Lapsed
US
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Digital bandpass oscilloscope
Assignee: Tektronix Inc
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Filing: 1987-04-03
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Granted: 1989-01-31
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Expires: 2007-04-03
Abstract
Abstract A digital bandpass oscilloscope permits an operator to observe both time and frequency domain plots of analog signal components of frequency within a passband of selected center frequency during a time window of selected duration. The input signal is digitized, and the resulting digital data sequence is bandpass filtered and decimated by an adjustable decimation ratio to produce stored waveform data indicating the time dependent behavior of the passband during the time window. The oscilloscope, which utilizes the waveform data to produce both time and frequency domain displays of the passband, adjusts the decimation ratio to ensure that the number of data elements in the waveform data sequence is constant regardless of the selected duration of the time window and adjusts the bandwidth of the passband to minimize aliasing in the time domain display.
Inventors
- 👤 Victor L. Hansen
- 👤 Shiv K. Balakrishnan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:26
CPC Classifications
G; G01; G01R; G01R13/00; G01R13/20; G01R13/22; G01R13/34; G01R13/345
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
84 words
A digital oscilloscope for displaying a representation of frequency components of an analog signal during a time window, the time window having an adjustable duration, the oscilloscope comprising: digitizing means responsive to said analog signal for generating a first data sequence representative of said analog signal during said time window; filter means responsive to said first data sequence for bandpass filtering and first data sequence to produce a second data sequence; and display means for displaying said representation according to said second data sequence.
Claim 2
Dependent Claim
84 words
A digital oscilloscope for displaying a representation of frequency components of an analog signal during a time window, the time window having an adjustable duration, the oscilloscope comprising: digitizing means responsive to said analog signal for generating a first data sequence representative of said analog signal during said time window; filter means responsive to said first data sequence for bandpass filtering and first data sequence to produce a second data sequence; and display means for displaying said representation according to said second data sequence.
Claim 3
Dependent Claim
34 words
The digital oscilloscope in accordance with claim 1 wherein said filter means has an adjustable bandwidth, said digital oscilloscope further comprising means for adjusting said bandwidth according to the duration of said time window.
Claim 4
Dependent Claim
61 words
The digital oscilloscope in accordance with claim 1 wherein said digitizing means comprises: a low pass filter for filtering said analog signal to produce an output signal; and means for periodically sampling said output signal at a constant sampling frequency to produce a sequence of voltage levels, and for generating said first data sequence according to said sequence of voltage levels.
Claim 5
Dependent Claim
24 words
The digital oscilloscope in accordance with claim 3 wherein said low pass filter has a bandwidth not greater than one half said sampling frequency.
Claim 6
Dependent Claim
93 words
A digital oscilloscope for displaying a representation of frequency components of an analog signal during a time window, the time window having an adjustable duration, the oscilloscope comprising: digitizing means responsive to said analog signal for generating a first data sequence representative of said analog signal during said time window; filter means responsive to said first data sequence for bandpass filtering and first data sequence according to an adjustable center frequency and an adjustable bandwidth to produce a second data sequence; and means for displaying said representation according to said second data sequence.
Claim 7
Dependent Claim
93 words
A digital oscilloscope for displaying a representation of frequency components of an analog signal during a time window, the time window having an adjustable duration, the oscilloscope comprising: digitizing means responsive to said analog signal for generating a first data sequence representative of said analog signal during said time window; filter means responsive to said first data sequence for bandpass filtering and first data sequence according to an adjustable center frequency and an adjustable bandwidth to produce a second data sequence; and means for displaying said representation according to said second data sequence.
Claim 8
Dependent Claim
35 words
The digital oscilloscope in accordance with claim 5 further comprising: means for adjusting said center frequency; and means for adjusting said bandwidth according to the duration of said time window and the adjusted center frequency.
Claim 9
Dependent Claim
94 words
A digital oscilloscope for displaying a representation of frequency components of an analog signal, the oscilloscope comprising: digitizing means responsive to said analog signal for generating a first data sequence representative of said analog signal during a time window of adjustable duration; and data processing means for quadrature modulating, lowpass filtering and decimating said first data sequence to produce waveform data, and for interpolating and quadrature demodulating said waveform data to produce a second data sequence representative of components of said analog signal included within a passband of adjustable center frequency and adjustable bandwidth.
Claim 10
Dependent Claim
94 words
A digital oscilloscope for displaying a representation of frequency components of an analog signal, the oscilloscope comprising: digitizing means responsive to said analog signal for generating a first data sequence representative of said analog signal during a time window of adjustable duration; and data processing means for quadrature modulating, lowpass filtering and decimating said first data sequence to produce waveform data, and for interpolating and quadrature demodulating said waveform data to produce a second data sequence representative of components of said analog signal included within a passband of adjustable center frequency and adjustable bandwidth.
Claim 11
Dependent Claim
18 words
The digital oscilloscope in accordance with claim 7 further comprising memory means for storing said waveform display data.
Claim 12
Dependent Claim
28 words
The digital oscilloscope in accordance with claim 7 further comprising means for displaying a time domain representation of said analog signal components according to said second data sequence.
Claim 13
Dependent Claim
45 words
The digital oscilloscope in accordance with claim 7 further comprising means for displaying a frequency domain representation of said analog signal components according to said waveform data, and for displaying a time domain representation of said analog signal components according to said second data sequence.
Claim 14
Dependent Claim
40 words
The digital oscilloscope in accordance with claim 7 wherein said data processing means comprises a filter for low pass filtering said first data sequence with an adjustable bandwidth, said bandwidth being adjusted according to the duration of said time window.
Claim 15
Dependent Claim
24 words
The digital oscilloscope in accordance with claim 7 wherein said data processing means decimates said first data sequence according to an adjustable decimation ratio.
Claim 16
Dependent Claim
22 words
The digital oscilloscope in accordance with claim 12 wherein said decimation ratio is adjusted according to the duration of said time window.
Claim 17
Dependent Claim
35 words
The digital oscilloscope in accordance with claim 7 wherein said data processing means decimates said first data sequence according to an adjustable decimation ratio and interpolates said waveform data according to an adjustable interpolation ratio.
Claim 18
Dependent Claim
24 words
The digital oscilloscope in accordance with claim 14 wherein said decimation and interpolation ratios are adjusted according to the duration of said time window.
Claim 19
Dependent Claim
120 words
A digital oscilloscope for displaying a representation of frequency components of an analog signal, the oscilloscope comprising: digitizing means responsive to said analog signal for generating a first data sequence representative of said analog signal during a time window of adjustable duration; data processing means for quadrature modulating, lowpass filtering and decimating said first data sequence to produce waveform data, and for interpolating and quadrature demodulating said waveform data to produce a second data sequence representative of components of said analog signal included within a frequency band of adjustable center frequency and adjustable bandwidth; means for storing said waveform display data; and means for displaying a time domain representation of said analog signal components according to said second data sequence.
Claim 20
Dependent Claim
120 words
A digital oscilloscope for displaying a representation of frequency components of an analog signal, the oscilloscope comprising: digitizing means responsive to said analog signal for generating a first data sequence representative of said analog signal during a time window of adjustable duration; data processing means for quadrature modulating, lowpass filtering and decimating said first data sequence to produce waveform data, and for interpolating and quadrature demodulating said waveform data to produce a second data sequence representative of components of said analog signal included within a frequency band of adjustable center frequency and adjustable bandwidth; means for storing said waveform display data; and means for displaying a time domain representation of said analog signal components according to said second data sequence.
Claim 21
Dependent Claim
27 words
The digital oscilloscope in accordance with claim 16 further comprising means for displaying a frequency domain representation of said analog signal components according to said waveform data.
Claim 22
Dependent Claim
93 words
The digital oscilloscope in accordance with claim 16 wherein said data processing means low pass filters and decimates said first data sequence with an adjustable bandwidth and according to an adjustable decimation ratio and interpolates said waveform data according to an adjustable interpolation ratio, said bandwidth, decimation ratio and interpolation ratio being adjusted according to the duration of said time window such that said time domain representation is substantially free of aliasing and such that said waveform data sequence includes a constant number of elements irrespective of the duration of said time window.
Claim 23
Independent Claim
76 words
A method for displaying a representation of frequency component os an analog signal during a time window, the time window having an adjustable duration, the method comprising the steps of: digitizing said analog signal to produce a first data sequence representative of said analog signal during said time window; bandpass filtering said first data sequence according to an adjustable bandwidth to produce a second data sequence; and displaying said representation according to said second data sequence.
Claim 24
Independent Claim
76 words
A method for displaying a representation of frequency component os an analog signal during a time window, the time window having an adjustable duration, the method comprising the steps of: digitizing said analog signal to produce a first data sequence representative of said analog signal during said time window; bandpass filtering said first data sequence according to an adjustable bandwidth to produce a second data sequence; and displaying said representation according to said second data sequence.
Claim 25
Dependent Claim
23 words
The method in accordance with claim 19 further comprising the step of adjusting said bandwidth according to the duration of said time window.
Claim 26
Dependent Claim
60 words
The method in accordance with claim 19 wherein the step of digitizing said analog signal comprises the substeps of: low pass filtering said analog signal to produce an output signal; periodically sampling said output signal at a constant sampling frequency to produce a sequence of voltage levels; and producing said first data sequence according to said sequence of voltage levels.
Claim 27
Dependent Claim
27 words
The method in accordance with claim 21 wherein said analog input signal is low pass filtered with a bandwidth not greater than one half said sampling frequency.
Claim 28
Independent Claim
80 words
A method for displaying a representation of time dependent behavior of frequency components of an analog signal during a time window, the time window having an adjustable duration, the method comprising the steps of: generating a first data sequence representative of said analog signal during said time window; bandpass filtering said first data sequence according to an adjustable center frequency and an adjustable bandwidth to produce a second data sequence; and displaying said representation according to said second data sequence.
Claim 29
Independent Claim
80 words
A method for displaying a representation of time dependent behavior of frequency components of an analog signal during a time window, the time window having an adjustable duration, the method comprising the steps of: generating a first data sequence representative of said analog signal during said time window; bandpass filtering said first data sequence according to an adjustable center frequency and an adjustable bandwidth to produce a second data sequence; and displaying said representation according to said second data sequence.
Claim 30
Dependent Claim
29 words
The method in accordance with claim 23 further comprising the step of adjusting said bandwidth according to the duration of said time window and according to said center frequency.
Claim 31
Independent Claim
114 words
A method for displaying a representation of frequency components of an analog signal, the method comprising the steps of: generating a first data sequence representative of said analog signal during a time window of adjustable duration; quadrature modulating said first data sequence to produce second and third data sequences; lowpass filtering and decimating said second and third data sequences to produce fourth and fifth data sequences; interpolating said fourth and fifth data sequences to produce sixth and seventh data sequences; and quadrature demodulating said sixth and seventh data sequences to produce an eighth data sequence representative of components of said analog signal included within a frequency band of adjustable center frequency and adjustable bandwidth.
Claim 32
Independent Claim
114 words
A method for displaying a representation of frequency components of an analog signal, the method comprising the steps of: generating a first data sequence representative of said analog signal during a time window of adjustable duration; quadrature modulating said first data sequence to produce second and third data sequences; lowpass filtering and decimating said second and third data sequences to produce fourth and fifth data sequences; interpolating said fourth and fifth data sequences to produce sixth and seventh data sequences; and quadrature demodulating said sixth and seventh data sequences to produce an eighth data sequence representative of components of said analog signal included within a frequency band of adjustable center frequency and adjustable bandwidth.
Claim 33
Dependent Claim
22 words
The method in accordance with claim 25 further comprising the step of storing said fourth and fifth data sequences in memory means.
Claim 34
Dependent Claim
28 words
The method in accordance with claim 25 further comprising the step of displaying a time domain representation of said analog signal components according to said eighth data sequence.
Claim 35
Dependent Claim
47 words
The method in accordance with claim 25 further comprising the steps of: displaying a frequency domain representation of said analog signal components according to said fourth and fifth data sequences, and displaying a time domain representation of said analog signal components according to said eights data sequence.
Claim 36
Dependent Claim
52 words
The method in accordance with claim 25 wherein said second and third data sequences are decimated according to an adjustable decimation ratio and said fourth and fifth data sequences are interpolated according to an adjustable interpolation ratio, said decimation and interpolation ratios being adjusted accorded to the duration of said time window.
Claim 37
Dependent Claim
35 words
The method in accordance with claim 25 wherein said second and third data sequences are lowpass filtered by a filter having an adjustable bandwidth, said bandwidth being adjusted according the duration of said time window.
Claim 38
Dependent Claim
22 words
The method in accordance with claim 25 wherein said second and third data sequences are decimated according to an adjustable decimation ratio.
Claim 39
Dependent Claim
24 words
The method in accordance with claim 31 further comprising the step of adjusting said decimation ratio according to the duration of said time window.
Claim 40
Independent Claim
140 words
A method for displaying a representation of frequency components of an analog signal, the method comprising the steps of: generating a first data sequence representative of said analog signal during a time window of adjustable duration; quadrature modulating said first data sequence to produce second and third data sequences; lowpass filtering and decimating said second and third data sequences to produce fourth and fifth data sequences; storing said fourth and fifth data sequences in memory means; interpolating said fourth and fifth data sequences to produce sixth and seventh data sequences; quadrature demodulating said sixth and seventh data sequences to produce an eighth data sequence representative of components of said analog signal included within a frequency band of adjustable center frequency and adjustable bandwidth; and displaying a time domain representation of said analog signal components according to said eighth data sequence.
Claim 41
Independent Claim
140 words
A method for displaying a representation of frequency components of an analog signal, the method comprising the steps of: generating a first data sequence representative of said analog signal during a time window of adjustable duration; quadrature modulating said first data sequence to produce second and third data sequences; lowpass filtering and decimating said second and third data sequences to produce fourth and fifth data sequences; storing said fourth and fifth data sequences in memory means; interpolating said fourth and fifth data sequences to produce sixth and seventh data sequences; quadrature demodulating said sixth and seventh data sequences to produce an eighth data sequence representative of components of said analog signal included within a frequency band of adjustable center frequency and adjustable bandwidth; and displaying a time domain representation of said analog signal components according to said eighth data sequence.
Claim 42
Dependent Claim
30 words
The method in accordance with claim 33 further comprising the step of displaying a frequency domain representation of said analog signal components according to said fourth and fifth data sequences.
Claim 43
Dependent Claim
81 words
The method in accordance with claim 33 wherein said second and third data sequences are decimated according to an adjustable decimation ratio and said fourth and fifth data sequences are interpolated according to an adjustable interpolation ratio, said decimation and interpolation ratios being adjusted according to the duration of said time window, and wherein said second and third data sequences are lowpass filtered by a filter having an adjustable bandwidth, said bandwidth being adjusted according the duration of said time window.
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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) | 1992-01-31 | 1992-08-01 | 1993-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-31 | 1996-08-01 | 1997-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-31 | 2000-08-01 | 2001-01-31 | $7700.00 | Window Closed / Lapsed |