US3573647A
Expired / Lapsed
US
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Electrical impedance converting networks
Assignee: HER MAJESTY S POSTMASTER GERER
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Filing: 1969-02-07
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Granted: 1971-04-06
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Expires: 1989-02-07
Abstract
Abstract This specification describes networks having gyrator properties. Each network comprises two differential amplifiers, and four resistors (conveniently equal) connected in positive and negative feedback paths about the amplifiers. The feedback connections are such that the networks are unconditionally stable. When a network is capacitively terminated it input port impedance is inductive. If in each of a group of capacitively terminated networks one of the feedback resistors is replaced by one of a group of input ports of a network of resistors the input ports of the gyrator networks simulate corresponding input ports of a network of inductors topologically and proportionally the same as the resistor network.
Inventors
- 👤 Andreas Antoniou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:29
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/40; H03H11/42
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
210 words
An electrical impedance network comprising two high-gain differential amplifiers, each having noninverting and inverting input terminals and an output terminal at which an output signal is produced relative to earth, a connection including a first impedance from the output terminal of one amplifier to the noninverting input terminal of the other amplifier, connections respectively including a first resistor and a second impedance from the output terminal of the other amplifier to the noninverting and inverting input terminals of the one amplifier, a negative feedback connection including a second resistor connected from the output terminal of the one amplifier to the inverting input terminal of the same amplifier, a connection including a third resistor from the noninverting input terminal of the other amplifier to earth, a pair of input terminals, one of which is earthed and the other of which is connected to the noninverting inPut terminal of the one amplifier, and a connection from the inverting input terminal of the other amplifier directly to an input terminal of the one amplifier, one of the first and second impedances being a resistor and the other being an output load impedance, whereby the network presents at its input terminals an impedance which is proportional to the inverse of the output load impedance.
Claim 2
Dependent Claim
210 words
An electrical impedance network comprising two high-gain differential amplifiers, each having noninverting and inverting input terminals and an output terminal at which an output signal is produced relative to earth, a connection including a first impedance from the output terminal of one amplifier to the noninverting input terminal of the other amplifier, connections respectively including a first resistor and a second impedance from the output terminal of the other amplifier to the noninverting and inverting input terminals of the one amplifier, a negative feedback connection including a second resistor connected from the output terminal of the one amplifier to the inverting input terminal of the same amplifier, a connection including a third resistor from the noninverting input terminal of the other amplifier to earth, a pair of input terminals, one of which is earthed and the other of which is connected to the noninverting inPut terminal of the one amplifier, and a connection from the inverting input terminal of the other amplifier directly to an input terminal of the one amplifier, one of the first and second impedances being a resistor and the other being an output load impedance, whereby the network presents at its input terminals an impedance which is proportional to the inverse of the output load impedance.
Claim 3
Dependent Claim
40 words
An electrical impedance network as claimed in claim 1 wherein the connection from the inverting input terminal of the other amplifier directly to an input terminal of the one amplifier is connected to the noninverting input terminal of that amplifier.
Claim 4
Dependent Claim
25 words
An electrical impedance network as claimed in claim 2 wherein the first impedance is a resistor, and the second impedance is the output load impedance.
Claim 5
Dependent Claim
25 words
An electrical impedance network as claimed in claim 2 wherein the first impedance is the output load impedance, and the second impedance is a resistor.
Claim 6
Dependent Claim
28 words
An electrical impedance network as claimed in claim 1 wherein the output load impedance is a capacitor so that the impedance at the input terminals is effectively inductive.
Claim 7
Dependent Claim
16 words
An electrical impedance network according to claim 5 wherein the four resistances are equal in value.
Claim 8
Dependent Claim
73 words
A circuit arrangement including a resistive network having a grounded terminal and a plurality of other terminals, a plurality of networks according to claim 6 in which the connections from the noninverting inputs of the other amplifiers to the third resistor are replaced by output connections respectively connected to the other terminals of the resistive network, whereby the circuit arrangement simulates a network of inductors topologically and quantitatively corresponding to the resistive network.
Claim 9
Dependent Claim
40 words
An electrical impedance network as claimed in claim 1 wherein the connection from the inverting input terminal of the other amplifier directly to an input terminal of the one amplifier is connected to the inverting input terminal of that amplifier.
Claim 10
Dependent Claim
25 words
An electrical impedance network as claimed in claim 8 wherein the first impedance is a resistor, and the second impedance is an output load impedance.
Claim 11
Dependent Claim
25 words
An electrical impedance network as claimed in claim 8 wherein the first impedance is the output load impedance, and the second impedance is a resistor.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-05 | 1974-10-05 | 1975-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-05 | 1978-10-05 | 1979-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-05 | 1982-10-05 | 1983-04-06 | $7700.00 | Window Closed / Lapsed |