US3605032A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active rc networks
Assignee: National Aeronautics and Space Administration
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Filing: 1970-05-04
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Granted: 1971-09-14
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Expires: 1990-05-04
Abstract
Abstract An active RC network formed by a voltage amplifier, a passive RC input circuit for the amplifier which circuit includes a distributed RC element, and a provision for positive feedback from the output of the amplifier to the input circuit. In one embodiment, a lumped capacitor is connected in shunt with the voltage amplifier whereby a pole of the network transfer function can be located at any desired position farther from the origin than a zero of the function. Another embodiment includes a lumped resistor, which is connected in shunt with the voltage amplifier, whereby a pole can be located at any desired position closer to the origin than the zero. In another embodiment, a pole is located simply by proper selection of the amplifier gain and the parameters of the distributed element; also the amplifier gain is always less than unity in this embodiment so that a very simple oscillator may be provided by location of the pole on the imaginary axis of the impedance plane. Still further embodiments provide for the distributed element to be advantageously divided into a plurality of sections. In view of the reduced gain requirements of the networks of this invention, the voltage amplifier may in many cases be a simple emitter follower, and an example of a network with such an amplifier is described. The networks may be connected in cascade to contribute separate factors in an overall response, and an example of the use of such cascaded networks to obtain a low-pass filter response is described.
Inventors
- 👤 William J Kerwin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:15
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/12; H03H11/1204
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
116 words
An active RC filter having conjugate poles of transmission independently positionable with respect to conjugate zeros of transmission comprising a positive gain voltage amplifier with an input and an output, first and secoNd input terminals, first and second output terminals, said output of said amplifier being connected to said first output terminal, said second input terminal being connected to said second output terminal, a distributed RC network having one resistance and one capacitance, said resistance being connected between said first input terminal and said amplifier input, a resistor connected between said amplifier output and one electrode of said capacitance in said RC network, and an impedance connected between said amplifier input and said second input terminal.
Claim 2
Dependent Claim
116 words
An active RC filter having conjugate poles of transmission independently positionable with respect to conjugate zeros of transmission comprising a positive gain voltage amplifier with an input and an output, first and secoNd input terminals, first and second output terminals, said output of said amplifier being connected to said first output terminal, said second input terminal being connected to said second output terminal, a distributed RC network having one resistance and one capacitance, said resistance being connected between said first input terminal and said amplifier input, a resistor connected between said amplifier output and one electrode of said capacitance in said RC network, and an impedance connected between said amplifier input and said second input terminal.
Claim 3
Dependent Claim
147 words
An active RC filter having conjugate poles of transmission independently positionable with respect to conjugate zeros of transmission comprising first and second input terminals, a positive gain voltage amplifier with an input and an output, first and second output terminals, said second input terminal being connected to said second output terminal, said amplifier output being connected to said first output terminal, a distributed RC network having a resistance and a capacitance, said resistance being connected between said first input terminal and said amplifier input, a resistor connected between said amplifier output and an electrode of said RC network capacitance, and an impedance connected between said amplifier input and said second input terminal, said conjugate zeros being on the j omega axis and the position of said poles with respect to said zeros being a function of said impedance and a function of the gain of said amplifier.
Claim 4
Dependent Claim
147 words
An active RC filter having conjugate poles of transmission independently positionable with respect to conjugate zeros of transmission comprising first and second input terminals, a positive gain voltage amplifier with an input and an output, first and second output terminals, said second input terminal being connected to said second output terminal, said amplifier output being connected to said first output terminal, a distributed RC network having a resistance and a capacitance, said resistance being connected between said first input terminal and said amplifier input, a resistor connected between said amplifier output and an electrode of said RC network capacitance, and an impedance connected between said amplifier input and said second input terminal, said conjugate zeros being on the j omega axis and the position of said poles with respect to said zeros being a function of said impedance and a function of the gain of said amplifier.
Claim 5
Dependent Claim
162 words
An active RC filter having conjugate j omega axis zeros and conjugate poles in the left half of the p plane comprising a positive gain voltage amplifier having an input and an output, first and second input terminals, first and second output terminals, said second input terminal being connected to said second output terminal, said amplifier output being connected to said first output terminal, a three-terminal distributed RC network comprising a resistance and a capacitance, a first resistor having two terminals, one terminal of said first resistor being connected to said output of said amplifier, said terminals of said distributed RC network being connected to said first input terminal, said amplifier input and said second terminal of said first resistor, respectively, a second resistor connected between said amplifier input and said second input terminal, the position of said poles in said p plane being a function of the gain of said amplifier and a function of the resistance of said second resistor.
Claim 6
Dependent Claim
162 words
An active RC filter having conjugate j omega axis zeros and conjugate poles in the left half of the p plane comprising a positive gain voltage amplifier having an input and an output, first and second input terminals, first and second output terminals, said second input terminal being connected to said second output terminal, said amplifier output being connected to said first output terminal, a three-terminal distributed RC network comprising a resistance and a capacitance, a first resistor having two terminals, one terminal of said first resistor being connected to said output of said amplifier, said terminals of said distributed RC network being connected to said first input terminal, said amplifier input and said second terminal of said first resistor, respectively, a second resistor connected between said amplifier input and said second input terminal, the position of said poles in said p plane being a function of the gain of said amplifier and a function of the resistance of said second resistor.
Claim 7
Dependent Claim
155 words
An active RC filter having conjugate j omega axis zeros and conjugate poles in the left-half of the p plane comprising a positive gain voltage amplifier having an input and an output, first and second input terminals, first and second output terminals, said second input terminal being connected to said second output terminal, said amplifier being connected to said first output terminal, a three-terminal distributed RC network comprising a resistance and a capacitance, a resistor having two terminals, one terminal of said resistor being connected to said output of said amplifier, said terminals of said distributed RC network being connected to said first input terminal, said amplifier input and said second terminal of said resistor, respectively, a capacitor connected between said amplifier input and said second input terminal, the position of said poles in said p plane being a function of the gain of said amplifier and a function of the capacitance of said capacitor.
Claim 8
Dependent Claim
155 words
An active RC filter having conjugate j omega axis zeros and conjugate poles in the left-half of the p plane comprising a positive gain voltage amplifier having an input and an output, first and second input terminals, first and second output terminals, said second input terminal being connected to said second output terminal, said amplifier being connected to said first output terminal, a three-terminal distributed RC network comprising a resistance and a capacitance, a resistor having two terminals, one terminal of said resistor being connected to said output of said amplifier, said terminals of said distributed RC network being connected to said first input terminal, said amplifier input and said second terminal of said resistor, respectively, a capacitor connected between said amplifier input and said second input terminal, the position of said poles in said p plane being a function of the gain of said amplifier and a function of the capacitance of said capacitor.
Claim 9
Dependent Claim
165 words
An active RC filter having conjugate j omega axis zeros and conjugate poles in the left half of the p plane comprising a positive gain voltage amplifier having an input and an output, first and second input terminals, first and second output terminals, said second input terminal being connected to said second output terminal, said amplifier output being connected to said first output terminal, a first resistor having Two terminals, one of said first resistor terminals being connected to said first output terminal, a distributed RC network having a resistance and a capacitance, said resistance being connected between said first input terminal and said amplifier input, an electrode of said RC network capacitance being connected to said other terminal of said first resistor, a second resistor connected between said amplifier input and said second output terminal, the position of said poles with respect to said zeros being a function of the gain of said amplifier and a function of the resistance of said second resistor.
Claim 10
Dependent Claim
165 words
An active RC filter having conjugate j omega axis zeros and conjugate poles in the left half of the p plane comprising a positive gain voltage amplifier having an input and an output, first and second input terminals, first and second output terminals, said second input terminal being connected to said second output terminal, said amplifier output being connected to said first output terminal, a first resistor having Two terminals, one of said first resistor terminals being connected to said first output terminal, a distributed RC network having a resistance and a capacitance, said resistance being connected between said first input terminal and said amplifier input, an electrode of said RC network capacitance being connected to said other terminal of said first resistor, a second resistor connected between said amplifier input and said second output terminal, the position of said poles with respect to said zeros being a function of the gain of said amplifier and a function of the resistance of said second resistor.
Claim 11
Dependent Claim
160 words
An active RC filter having conjugate j omega axis zeros and conjugate poles in the left half of the p plane comprising a positive gain voltage amplifier having an input and an output, first and second input terminals, first and second output terminals, said second input terminal being connected to said second output terminal, said amplifier output being connected to said first output terminal, a resistor having first and second terminals, said first resistor terminal being connected to said first output terminal, a distributed RC network having a resistance and a capacitance, said resistance being connected between said first input terminal and said amplifier input, an electrode of said RC network capacitance being connected to said second terminals of said resistor, a capacitor connected between said amplifier input and said second output terminal, the location of said poles with respect to zeros being a function of the gain of said amplifier and a function of the capacitance of said capacitor.
Claim 12
Dependent Claim
160 words
An active RC filter having conjugate j omega axis zeros and conjugate poles in the left half of the p plane comprising a positive gain voltage amplifier having an input and an output, first and second input terminals, first and second output terminals, said second input terminal being connected to said second output terminal, said amplifier output being connected to said first output terminal, a resistor having first and second terminals, said first resistor terminal being connected to said first output terminal, a distributed RC network having a resistance and a capacitance, said resistance being connected between said first input terminal and said amplifier input, an electrode of said RC network capacitance being connected to said second terminals of said resistor, a capacitor connected between said amplifier input and said second output terminal, the location of said poles with respect to zeros being a function of the gain of said amplifier and a function of the capacitance of said capacitor.
Claim 13
Dependent Claim
117 words
An active RC filter comprising: an amplifier with an input and an output, first and second input terminals, first and second output terminals, said second input terminal being connected to said second output terminal, said output of said amplifier being connected to said first output terminal, a distributed RC network having one resistance and first, second and third capacitances, each capacitance being adjacent to different sections of said resistance, said resistance being connected between said second input terminal and said amplifier input, said first, second and third capacitances being connected to said first input terminal, said second input terminal and said amplifier output, respectively, said active RC filter providing a second-order band-pass function with a high Q.
Claim 14
Dependent Claim
117 words
An active RC filter comprising: an amplifier with an input and an output, first and second input terminals, first and second output terminals, said second input terminal being connected to said second output terminal, said output of said amplifier being connected to said first output terminal, a distributed RC network having one resistance and first, second and third capacitances, each capacitance being adjacent to different sections of said resistance, said resistance being connected between said second input terminal and said amplifier input, said first, second and third capacitances being connected to said first input terminal, said second input terminal and said amplifier output, respectively, said active RC filter providing a second-order band-pass function with a high Q.
References Cited (Backward Citations)
US3389349A
Cited
US3473141A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |