US3660772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wide-band direct current coupled amplifier for alternating current utility
Assignee: Hickok Electrical Instrument Co
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Filing: 1970-05-13
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Granted: 1972-05-02
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Expires: 1990-05-13
Abstract
Abstract A wide-band direct-current-coupled amplifier for alternating current use having substantially flat operating characteristics and a high signal-to-noise ratio between input and output signal levels; the amplifier consisting of a high impedance input stage formed of a capacitive divider coupled to three FETs connected into a triple cascode circuit, which input stage, in turn, is connected to a cascoded differential amplifier; the output stage being an emitter follower. Suitable feedback which is adjustable for each operating range throughout the band is effective to provide an output signal that varies linearly in proportion to the input signal.
Inventors
- 👤 Frederick Rodney Holt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:13
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/45; H03F3/45071; H03F3/45076; H03F3/4508; H03F3/45085; H03F3/189; H03F3/19; H03F3/193; H03F3/1935
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
170 words
A wide-band, direct-coupled, multi-stage amplifier comprising a direct current supply, a first stage for receiving an input alternating current signal connected to said supply and including a first FET transistor connected in its common source configuration, a second FET transistor connected in its common gate configuration in series with said first transistor to define a cascode pair, a third FET transistor connected as a constant current generator between said second transistor and said supply to provide direct current stabilization, differential amplifier means direct coupled to the second transistor of said cascode pair, fourth transistor means connected to said differential amplifier means and defining the output of said amplifier, first feedback circuit means connected between said fourth transistor means and said first and second transistors effective to provide an increased gain of said series connected cascode pair of said first and second transistors, and second direct current negative feedback circuit means connected between said fourth transistor means and said third transistor effective to provide dIrect current stabilization for said second transistor.
Claim 2
Dependent Claim
170 words
A wide-band, direct-coupled, multi-stage amplifier comprising a direct current supply, a first stage for receiving an input alternating current signal connected to said supply and including a first FET transistor connected in its common source configuration, a second FET transistor connected in its common gate configuration in series with said first transistor to define a cascode pair, a third FET transistor connected as a constant current generator between said second transistor and said supply to provide direct current stabilization, differential amplifier means direct coupled to the second transistor of said cascode pair, fourth transistor means connected to said differential amplifier means and defining the output of said amplifier, first feedback circuit means connected between said fourth transistor means and said first and second transistors effective to provide an increased gain of said series connected cascode pair of said first and second transistors, and second direct current negative feedback circuit means connected between said fourth transistor means and said third transistor effective to provide dIrect current stabilization for said second transistor.
Claim 3
Dependent Claim
32 words
In a wide-band direct-coupled multi-stage amplifier as is defined in claim 1 and wherein attenuator means are connected to the first stage effective to attenuate a predetermined part of the input signal.
Claim 4
Dependent Claim
21 words
In a wide-band direct-coupled multi-stage amplifier as is defined in claim 2 and wherein the attenuator means includes a capacitive divide.
Claim 5
Dependent Claim
37 words
In a wide-band direct-coupled multi-stage amplifier as is defined in claim 3 and wherein the capacitive divide includes two capacitors in parallel and which are effective to attenuate the input signal within the range of 99.9 percent.
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) | 1975-05-02 | 1975-11-01 | 1976-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-02 | 1979-11-01 | 1980-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-02 | 1983-11-01 | 1984-05-02 | $7700.00 | Window Closed / Lapsed |