US3733514A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wide band amplifier having two separate high and low frequency paths for driving capacitive load with large amplitude signal
Assignee: Tektronix Inc
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Filing: 1971-03-19
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Granted: 1973-05-15
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Expires: 1991-03-19
Abstract
Abstract A wide frequency bandwidth amplifier circuit for driving an output load capacitance with large amplitude signals is described in which two separate paths are provided for low frequency and high frequency portions of such signal. The low frequency path is provided by a shunt feedback amplifier connected as an operational amplifier, while the high frequency path is formed by a series feedback amplifier. The gain of the series feedback amplifier, determined by the ratio of its series feedback capacitance divided by the output load capacitance, is made equal to the gain of the operational amplifier, determined by the ratio of its shunt feedback resistance divided by its input coupling resistance. The low frequency cutoff of the high frequency path is above the high frequency cutoff of the low frequency path. Thus, in one embodiment of the amplifier circuit with a frequency response of D.C. to 200 megahertz, the high frequency path has a response of one megahertz to 200 megahertz and the low frequency path has a response of D.C. to 30 megahertz. This embodiment is used as a horizontal sweep amplifier for driving the horizontal deflection plates of a cathode ray oscilloscope with a ramp shaped output signal of 80 volts amplitude and three nanoseconds rise time.
Inventors
- 👤 V Garuts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:03
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/189; H03F3/19; H03F1/00; H03F1/08; H03F1/22; H03F1/34; H03F1/42; H03F1/48; H03F3/34; H03F2200/00; H03F2200/39
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
111 words
An amplifier circuit having a load capacitance connected to its output terminal in which the improvement comprises: first means for providing a low frequency signal path D.C. coupled between The input and output terminals of said amplifier circuit; second means for providing a high frequency signal path between said input and output terminals with at least a portion of said high frequency path being separate from said low frequency path; said high frequency path and said low frequency path being of substantially the same gain; and said high frequency path having a low frequency cutoff below the high frequency cutoff of said low frequency path so that their frequency ranges overlap.
Claim 2
Dependent Claim
111 words
An amplifier circuit having a load capacitance connected to its output terminal in which the improvement comprises: first means for providing a low frequency signal path D.C. coupled between The input and output terminals of said amplifier circuit; second means for providing a high frequency signal path between said input and output terminals with at least a portion of said high frequency path being separate from said low frequency path; said high frequency path and said low frequency path being of substantially the same gain; and said high frequency path having a low frequency cutoff below the high frequency cutoff of said low frequency path so that their frequency ranges overlap.
Claim 3
Dependent Claim
131 words
An amplifier circuit having a load capacitance connected to its output terminal in which the improvement comprises: first means including a first negative feedback amplifier having a shunt feedback impedance connected between its input and output for providing a low frequency signal path between the input and output terminals of said amplifier circuit; second means including a second negative feedback amplifier having a series feedback impedance for providing a high frequency signal path between said input and output terminals with at least a portion of said high frequency path being separate from said low frequency path; said high frequency path and said low frequency path being of substantially the same gain; and said high frequency path having a low frequency cutoff below the high frequency cutoff of said low frequency path.
Claim 4
Dependent Claim
131 words
An amplifier circuit having a load capacitance connected to its output terminal in which the improvement comprises: first means including a first negative feedback amplifier having a shunt feedback impedance connected between its input and output for providing a low frequency signal path between the input and output terminals of said amplifier circuit; second means including a second negative feedback amplifier having a series feedback impedance for providing a high frequency signal path between said input and output terminals with at least a portion of said high frequency path being separate from said low frequency path; said high frequency path and said low frequency path being of substantially the same gain; and said high frequency path having a low frequency cutoff below the high frequency cutoff of said low frequency path.
Claim 5
Dependent Claim
60 words
An amplifier circuit in accordance with claim 2 in which the first feedback amplifier includes an input amplifier device connected as a phase inverter amplifier whose input is connected to said input terminal, and an output amplifier device connected as a noninverting voltage amplifier in cascade with said input amplifier device and having its output connected to said output terminal.
Claim 6
Dependent Claim
25 words
An amplifier circuit in accordance with claim 3 in which the second feedback amplifier includes a third amplifier device connected as a phase inverter amplifier.
Claim 7
Dependent Claim
50 words
An amplifier circuit in accordance with claim 4 in which the output amplifier device is an output transistor connected as a common base amplifier, and the input amplifier device is an input transistor connected as a common emitter amplifier with its collector connected to the emitter of said output transistor.
Claim 8
Dependent Claim
60 words
An amplifier circuit in accordance with claim 5 in which the first feedback amplifier is a D.C. coupled operational amplifier including a coupling resistor connected between the base of said input transistor and said input terminal, and the shunt feedback impedance is a feedback resistor connected between the collector of said output transistor and the base of said input transistor.
Claim 9
Dependent Claim
49 words
An amplifier circuit in accordance with claim 6 in which the third amplifier device is a third transistor connected as a common emitter amplifier having its base connected to said input terminal, and the series feedback impedance is a feedback capacitor connected to the emitter of said third transistor.
Claim 10
Dependent Claim
35 words
An amplifier circuit in accordance with claim 7 in which the ratio of the feedback capacitor to the load capacitance is substantially the same as the ratio of the feedback resistor to the coupling resistor.
Claim 11
Dependent Claim
56 words
An amplifier circuit in accordance with claim 7 in which the third transistor has its collector connected to a common connection at the collector of the input transistor and the emitter of the output transistor so that said output transistor forms a common path portion in both the low frequency path and the high frequency path.
Claim 12
Dependent Claim
51 words
An amplifier circuit in accordance with claim 9 which also has a plurality of sources of D.C. supply current including a first source connected to the collector of said output transistor, a second source connected to said common connection, and a third source connected to the emitter of said third transistor.
Claim 13
Dependent Claim
55 words
An amplifier circuit in accordance with claim 7 in which the third transistor has its collector connected to the emitter of a fourth transistor connected as a common base amplifier whose collector is connected to tHe output terminal so that the high frequency path is entirely separate from and parallel to the low frequency path.
Claim 14
Dependent Claim
29 words
An amplifier circuit in accordance with claim 11 in which a coupling capacitor is connected between the collector of said third transistor and the emitter of said fourth transistor.
Claim 15
Dependent Claim
76 words
An amplifier circuit in accordance with claim 12 which also has a plurality of sources of D.C. supply current including a first source connected to the emitter of the fourth transistor, a second source connected to the collector of the third transistor, a third source connected to the emitter of said third transistor, and a fourth source connected to a common connection at the collector of the output transistor and the collector of said fourth transistor.
Claim 16
Dependent Claim
30 words
An amplifier circuit in accordance with claim 2 in which the output terminal is connected to the horizontal deflection plates of a cathode ray tube to provide said load capacitance.
Claim 17
Dependent Claim
24 words
An amplifier circuit in accordance with claim 2 in which the output terminal is connected to the control grid of a cathode ray tube.
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) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |