US4340866A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermally-compensated variable gain differential amplifier
Assignee: Tektronix Inc
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Filing: 1979-09-17
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Granted: 1982-07-20
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Expires: 1999-09-17
Abstract
Abstract A linear wideband differential amplifier includes a variable gain stage comprising two cross-coupled differential amplifiers and differential current source to compensate for thermal distortion, to minimize transient response distortion, and to eliminate signal attenuation at the center gain setting.
Inventors
- 👤 Arthur J. Metz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:58
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/45; H03F3/45071; H03F3/45076; H03F3/45179; H03F3/45197; H03F1/00; H03F1/32; H03F1/3211
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
136 words
A thermal-compensated variable-gain differential amplifier, comprising: a pair of common-base amplifier input transistors for receiving input currents at the emitters thereof; a first emitter-coupled pair of transistors connected between the emitters of said pair of input transistors, the collectors of said first emitter-coupled pair of transistors being cross-coupled to the collectors of said input transistors; a second emitter-coupled pair of transistors connected between the emitters of said pair of input transistors, the collectors of said second emitter-coupled pair of transistors being coupled to the cross-coupled collectors of said first emitter-coupled pair of transistors and to the collectors of said pair of input transistors; and differential current generator means for providing first and second variably adjustable complementary operating currents, said first and second operating currents being provided to said first and second emitter-coupled pairs of transistors respectively.
Claim 2
Dependent Claim
136 words
A thermal-compensated variable-gain differential amplifier, comprising: a pair of common-base amplifier input transistors for receiving input currents at the emitters thereof; a first emitter-coupled pair of transistors connected between the emitters of said pair of input transistors, the collectors of said first emitter-coupled pair of transistors being cross-coupled to the collectors of said input transistors; a second emitter-coupled pair of transistors connected between the emitters of said pair of input transistors, the collectors of said second emitter-coupled pair of transistors being coupled to the cross-coupled collectors of said first emitter-coupled pair of transistors and to the collectors of said pair of input transistors; and differential current generator means for providing first and second variably adjustable complementary operating currents, said first and second operating currents being provided to said first and second emitter-coupled pairs of transistors respectively.
Claim 3
Dependent Claim
49 words
An amplifier in accordance with claim 1 wherein the ratio of the emitter area of said pair of input transistors to either of said first and second emitter-coupled pairs of transistors is equal to ratio of the sum of said input currents to the sum of said operating currents.
Claim 4
Dependent Claim
28 words
An amplifier in accordance with claim 1 further including a pair of common-base amplifier output transistors connected to the collectors of said pair of common-base amplifier input transistors.
Claim 5
Dependent Claim
33 words
An amplifier in accordance with claim 1 further including means for providing substantially fixed and identical collector-to-emitter voltages for said pair of input transistors and said first and second emitter-coupled pairs of transistors.
References Cited (Backward Citations)
US3684974A
Cited
US3689752A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-07-19 | 1986-01-18 | 1986-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-19 | 1990-01-18 | 1990-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-19 | 1994-01-18 | 1994-07-20 | $7700.00 | Window Closed / Lapsed |