US3573644A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dc stabilized wide band amplifier
Assignee: HP Inc
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Filing: 1969-03-20
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Granted: 1971-04-06
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Expires: 1989-03-20
Abstract
Abstract A wideband stabilized wide band amplifier is constructed to have two signal paths, one designed for optimum high-frequency performance and the other designed for optimum low frequency and DC performance. The signals in the two paths are combined in a differential amplifier and the output fed back to the DC signal path in such a manner that any DC signal drift in the AC signal path is reduced.
Inventors
- 👤 Eddie A Evel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:43
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/30; H03F1/42; H03F1/48; H03F1/486; H03F3/00; H03F3/34; H03F3/343; H03F3/347
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
263 words
In an amplifier system having a signal input terminal and a signal output terminal, the combination of: a differential amplifier having first and second inputs, and an output coupled to said system signal output terminal, said differential amplifier having a linear, wide bandwidth alternating current frequency response and a predetermined gain; first circuit means for coupling the first input of said differential amplifier to said system signal input terminal, said first circuit means including an alternating current amplifier having a wide bandwidth frequency response and a predetermined gain; second circuit means for coupling the second input of said differential amplifier to said system signal input terminal, said second circuit means including: a direct current amplifier having an input and an output, said output being coupled to the second input of said differential amplifier, said direct current amplifier having a predetermined gain; a direct current operational amplifier having an input and an output, said input being coupled to said system signal input terminal, said operational amplifier having a selectable gain; and impedance means for coupling the input of said first-named direct current amplifier to the output of said direct current operational amplifier; a single feedback path including feedback impedance means for coupling the output of said differential amplifier to the input of said first-named direct current amplifier; and said second circuit means and said feedback impedance means being operable to provide a feedback signal having a magnitude which is a decreasing function of the frequency of the signal applied to said system input terminal to override any direct current drift in said differential amplifier.
Claim 2
Dependent Claim
263 words
In an amplifier system having a signal input terminal and a signal output terminal, the combination of: a differential amplifier having first and second inputs, and an output coupled to said system signal output terminal, said differential amplifier having a linear, wide bandwidth alternating current frequency response and a predetermined gain; first circuit means for coupling the first input of said differential amplifier to said system signal input terminal, said first circuit means including an alternating current amplifier having a wide bandwidth frequency response and a predetermined gain; second circuit means for coupling the second input of said differential amplifier to said system signal input terminal, said second circuit means including: a direct current amplifier having an input and an output, said output being coupled to the second input of said differential amplifier, said direct current amplifier having a predetermined gain; a direct current operational amplifier having an input and an output, said input being coupled to said system signal input terminal, said operational amplifier having a selectable gain; and impedance means for coupling the input of said first-named direct current amplifier to the output of said direct current operational amplifier; a single feedback path including feedback impedance means for coupling the output of said differential amplifier to the input of said first-named direct current amplifier; and said second circuit means and said feedback impedance means being operable to provide a feedback signal having a magnitude which is a decreasing function of the frequency of the signal applied to said system input terminal to override any direct current drift in said differential amplifier.
Claim 3
Dependent Claim
51 words
A system according to claim 1 wherein the product of the gains of said alternating current amplifier and said differential amplifier is substantially equal to the product of the gains of said direct current amplifiers whereby the gain of said system is substantially independent of the frequEncy of the input signal.
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) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |