Patent US3833856A successfully refreshed from Google Patents.
US3833856A
Expired / Lapsed
US
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Apparatus for testing an amplifier
Assignee: United States Department of the Navy
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Filing: 1973-11-15
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Granted: 1974-09-03
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Expires: 1993-11-15
Abstract
Abstract A testing device for measuring phase shift and amplitude changes in an amplifier. A frequency synthesizer provides a sine wave through first and second channels with the amplifier being connected in the first channel. The outputs from the first and second channels are applied to a computer for analysis. The computer is programmed to calculate the phase angles for the waveforms. The difference in these phase angles is the phase shift of the amplifier under test, and this difference is presented in a readout device.
Inventors
- 👤 E Roeschlein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:23
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/28; G01R31/00; G01R31/26
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
195 words
A device for measuring phase shift of an amplifier comprising, a frequency synthesizer selectively providing an output signal at any one of a plurality of frequencies, a countdown circuit connected to said frequency synthesizer for dividing the selected frequency and providing a plurality of outputs, memory means addressed by the outputs of said countdown circuit for providing digital word outputs representing a sine function of one cycle, converter means connected to the outputs of said memory means for providing a sine wave to an input of said amplifier, first and second analog to digital converters, a first circuit path connected between said input of said amplifier and said first analog to digital converter and a second circuit path connected between the output of said amplifier and said second analog to digital converter, and computing means connected to the outputs of said first and second analog to digital converters for calculating the phase angle of the sine wave passing through said first circuit path and the phase angle of the sine wave passing through said second circuit path and for taking the difference between the two phase angles to determine the phase shift of said amplifier.
Claim 2
Independent Claim
195 words
A device for measuring phase shift of an amplifier comprising, a frequency synthesizer selectively providing an output signal at any one of a plurality of frequencies, a countdown circuit connected to said frequency synthesizer for dividing the selected frequency and providing a plurality of outputs, memory means addressed by the outputs of said countdown circuit for providing digital word outputs representing a sine function of one cycle, converter means connected to the outputs of said memory means for providing a sine wave to an input of said amplifier, first and second analog to digital converters, a first circuit path connected between said input of said amplifier and said first analog to digital converter and a second circuit path connected between the output of said amplifier and said second analog to digital converter, and computing means connected to the outputs of said first and second analog to digital converters for calculating the phase angle of the sine wave passing through said first circuit path and the phase angle of the sine wave passing through said second circuit path and for taking the difference between the two phase angles to determine the phase shift of said amplifier.
Claim 3
Dependent Claim
30 words
A device for measuring phase shift of an amplifier as set forth in claim 1 wherein said computing means selects the frequency of said output signal of said frequency synthesizer.
Claim 4
Dependent Claim
39 words
A device for measuring phase syqft shift an amplifier as set forth in claim 1 having a second countdown circuit connected to said frequency synthesizer for generating a sample pulse for said first and second analog to digital converters.
Claim 5
Dependent Claim
23 words
A device for measuring phase shift of an amplifier as set forth in claim 1 having readout means connected to said computing means.
Claim 6
Dependent Claim
40 words
A device for measuring phase shift of an amplifier as set forth in claim 3 wherein said first and second countdown circuits are dividers having a ratio slightly less than a whole number thereby causing precession of said sample pulse.
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) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |