US4823090A
Expired / Lapsed
US
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Digital signal synthesis using low frequency sampling clock
Assignee: Tektronix Inc
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Filing: 1987-10-02
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Granted: 1989-04-18
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Expires: 2007-10-02
Abstract
Abstract A digital signal synthesizer stores a representation of a desired analog signal in the form of digital samples. The digital samples are converted to an analog signal by a sample clock having a frequency greater than or equal to twice the bandwidth of the desired analog signal. The analog signal is band pass filtered to recover the desired analog signal.
Inventors
- 👤 Mike R. Coleman
- 👤 John J. Ciardi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:09
CPC Classifications
G; G06; G06F; G06F1/00; G06F1/02; G06F1/03; G06F1/0321; H; H03; H03C; H03C1/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
86 words
A digital signal synthesizer for generating a desired analog signal having a predetermined frequency and bandwidth from digital samples representing the desired analog signal comprising: means for storing the digital samples; means for converting the digital samples from the storing means to an analog signal at a rate which is greater than or equal to twice the bandwidth of the desired analog signal; and means for band pass filtering the analog signal from the converting means around the predetermined frequency to produce the desired analog signal.
Claim 2
Dependent Claim
86 words
A digital signal synthesizer for generating a desired analog signal having a predetermined frequency and bandwidth from digital samples representing the desired analog signal comprising: means for storing the digital samples; means for converting the digital samples from the storing means to an analog signal at a rate which is greater than or equal to twice the bandwidth of the desired analog signal; and means for band pass filtering the analog signal from the converting means around the predetermined frequency to produce the desired analog signal.
Claim 3
Dependent Claim
121 words
A calibration circuit for generating a modulated high frequency subcarrier and baseband signals comprising: means for storing a representation of the modulated high frequency subcarrier and baseband signals in the form of digital samples; means for converting the digital samples from the storing means to an analog signal at a rate which is greater than or equal to twice the bandwidth of the modulated high frequency subcarrier and baseband signals; means for resampling the analog signal from the converting means to produce an impulsive analog signal; means for filtering the impulsive analog signal from the resampling means to produce a sinusoid analog signal; and means for separating the sinusoid analog signal into the modulated high frequency subcarrier and the baseband signals.
Claim 4
Dependent Claim
121 words
A calibration circuit for generating a modulated high frequency subcarrier and baseband signals comprising: means for storing a representation of the modulated high frequency subcarrier and baseband signals in the form of digital samples; means for converting the digital samples from the storing means to an analog signal at a rate which is greater than or equal to twice the bandwidth of the modulated high frequency subcarrier and baseband signals; means for resampling the analog signal from the converting means to produce an impulsive analog signal; means for filtering the impulsive analog signal from the resampling means to produce a sinusoid analog signal; and means for separating the sinusoid analog signal into the modulated high frequency subcarrier and the baseband signals.
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) | 1992-04-17 | 1992-10-17 | 1993-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-17 | 1996-10-17 | 1997-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-17 | 2000-10-17 | 2001-04-18 | $7700.00 | Window Closed / Lapsed |