US3969682A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for dynamic control of phase shift
Assignee: OBERHEIM ELECTRONICS Inc
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Filing: 1974-10-21
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Granted: 1976-07-13
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Expires: 1994-10-21
Abstract
Abstract A current controlled variable transconductance amplifier having a differential input stage and a current source output stage is employed with negative feedback, either through a buffer amplifier or directly, to provide various all-pass, low-pass or high-pass filter configurations, each with controlled bias current to the differential input stage for current control of the variable transconductance amplifier to provide dynamic control of phase shift and filter cutoff frequency.
Inventors
- 👤 David Philip Rossum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:47
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/16; H03H11/20
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
188 words
A circuit for dynamic control of phase shift of a signal between input and output terminals thereof comprising a variable tranconductance amplifier, said transconductance amplifier having a differential input stage with separate inverting and noninverting input terminals, and a current source output stage, a capacitor connected between the output of said transconductance amplifier and said circuit input terminal to receive a signal from the output of said transconductance amplifier, means for coupling a signal from said circuit input terminal to an input terminal of said transconductance amplifier, a noninverting buffer amplifier having high input impedance for coupling the output of said transconductance amplifier to said circuit output terminal, a direct current path between said circuit output terminal and said inverting input terminal of said transconductance amplifier for coupling negative feedback from the output of said transconductance amplifier to an input thereof, and means for supplying a variable control bias current to said amplifier for phase shift monotonically related to said bias current, said noninverting input terminal of said transconductance amplifier being connected to circuit ground and said inverting input terminal being connected to said negative feedback coupling means.
Claim 2
Dependent Claim
188 words
A circuit for dynamic control of phase shift of a signal between input and output terminals thereof comprising a variable tranconductance amplifier, said transconductance amplifier having a differential input stage with separate inverting and noninverting input terminals, and a current source output stage, a capacitor connected between the output of said transconductance amplifier and said circuit input terminal to receive a signal from the output of said transconductance amplifier, means for coupling a signal from said circuit input terminal to an input terminal of said transconductance amplifier, a noninverting buffer amplifier having high input impedance for coupling the output of said transconductance amplifier to said circuit output terminal, a direct current path between said circuit output terminal and said inverting input terminal of said transconductance amplifier for coupling negative feedback from the output of said transconductance amplifier to an input thereof, and means for supplying a variable control bias current to said amplifier for phase shift monotonically related to said bias current, said noninverting input terminal of said transconductance amplifier being connected to circuit ground and said inverting input terminal being connected to said negative feedback coupling means.
Claim 3
Dependent Claim
59 words
A circuit as defined in claim 1 wherein said output terminal of said buffer amplifier is connected to said inverting input terminal of said transconductance amplifier through a voltage dividing network comprised of a series resistor connected to said inverting input terminal of said transconductance amplifier, and a shunt resistor connected between said inverting input terminal and circuit ground.
Claim 4
Dependent Claim
27 words
A circuit as defined in claim 2 wherein said circuit input terminal is connected to said inverting input terminal of said transconductance amplifier by a series resistor.
Claim 5
Dependent Claim
189 words
A circuit for dynamic control of phase shift of a signal between input and output terminals thereof comprising a variable transconductance amplifier, a capacitor connected between the output of said transconductance amplifier and said circuit input terminal to receive a signal from the output of said transconductance amplifier, means for coupling a signal from said circuit input terminal to an input terminal of said transconductance amplifier, means for coupling the output of said transconductance amplifier to said circuit output terminal, means for coupling negative feedback from the output of said transconductance amplifier to an input thereof, and means for supplying a variable control bias current to said amplifier for a phase shift monotonically related to said bias current, said transconductance amplifier having a differential input stage with separate inverting and noninverting input terminals, and a current source output stage, said inverting input terminal being connected to circuit ground through a shunt resistor and being connected to receive said negative feedback through a series resistor, said noninverting input terminal being connected to circuit ground, and said circuit input terminal being connected to said inverting input terminal through a series resistor.
Claim 6
Dependent Claim
189 words
A circuit for dynamic control of phase shift of a signal between input and output terminals thereof comprising a variable transconductance amplifier, a capacitor connected between the output of said transconductance amplifier and said circuit input terminal to receive a signal from the output of said transconductance amplifier, means for coupling a signal from said circuit input terminal to an input terminal of said transconductance amplifier, means for coupling the output of said transconductance amplifier to said circuit output terminal, means for coupling negative feedback from the output of said transconductance amplifier to an input thereof, and means for supplying a variable control bias current to said amplifier for a phase shift monotonically related to said bias current, said transconductance amplifier having a differential input stage with separate inverting and noninverting input terminals, and a current source output stage, said inverting input terminal being connected to circuit ground through a shunt resistor and being connected to receive said negative feedback through a series resistor, said noninverting input terminal being connected to circuit ground, and said circuit input terminal being connected to said inverting input terminal through a series resistor.
Claim 7
Dependent Claim
158 words
A circuit for dynamic control of phase shift of a signal between input and output terminals thereof comprising a variable transconductance amplifier having a differential input stage with separate inverting and noninverting input terminals, and a current source output stage, said noninverting input terminal being connected to circuit ground, a capacitor connected in series between said circuit input terminal and the output of said transconductance amplifier, impedance matching means for coupling the output of said amplifier to said circuit output terminal comprised of a noninverting buffer amplifier having high input impedance, means for coupling negative feedback from the output of said transconductance amplifier to the input thereof comprised of a direct current path between said circuit output terminal and said inverting input terminal of said transconductance amplifier, and means for supplying a variable control bias current to said amplifier for a phase shift of said signal translated by said circuit from said input terminal to said output terminal.
Claim 8
Dependent Claim
158 words
A circuit for dynamic control of phase shift of a signal between input and output terminals thereof comprising a variable transconductance amplifier having a differential input stage with separate inverting and noninverting input terminals, and a current source output stage, said noninverting input terminal being connected to circuit ground, a capacitor connected in series between said circuit input terminal and the output of said transconductance amplifier, impedance matching means for coupling the output of said amplifier to said circuit output terminal comprised of a noninverting buffer amplifier having high input impedance, means for coupling negative feedback from the output of said transconductance amplifier to the input thereof comprised of a direct current path between said circuit output terminal and said inverting input terminal of said transconductance amplifier, and means for supplying a variable control bias current to said amplifier for a phase shift of said signal translated by said circuit from said input terminal to said output terminal.
Claim 9
Dependent Claim
64 words
A circuit as defined in claim 5 wherein said output terminal of said buffer amplifier is connected to said inverting input terminal of said differential input stage of said transconductance amplifier through a voltage dividing network comprised of a series resistor connected to said inverting input terminal of said transconductance amplifier, and a shunt resistor connected between said inverting input terminal and circuit ground.
Claim 10
Dependent Claim
34 words
A circuit as defined in claim 5 wherein said negative feedback coupling means is comprised of a direct connection from said current source output stage to said inverting input terminal of said transconductance amplifier.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-07-13 | 1980-01-12 | 1980-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-13 | 1984-01-12 | 1984-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-13 | 1988-01-12 | 1988-07-13 | $7700.00 | Window Closed / Lapsed |