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Patent US4151493A successfully refreshed from Google Patents.
US4151493A
Expired / Lapsed
US
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Negative impedance converters
Assignee: Nortel Networks Ltd
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Filing: 1977-10-03
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Granted: 1979-04-24
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Expires: 1997-10-03
Abstract
Abstract An improved negative impedance converter is provided comprising an additional differential operational amplifier to improve signal handling capability.
Inventors
- 👤 Ted J. Lewandowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:26
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/40; H03H11/44
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
76 words
An improved negative impedance converter comprising: a conventional negative impedance converter having a negative impedance port and a positive impedance port; a first differential operational amplifier having an inverting input and a non-inverting input and an output; said inverting input receiving one side of said negative impedance port; said non-inverting input receiving a reference voltage; and said output forming, with the other side of said negative impedance port, the output of said improved negative impedance converter.
Claim 2
Dependent Claim
76 words
An improved negative impedance converter comprising: a conventional negative impedance converter having a negative impedance port and a positive impedance port; a first differential operational amplifier having an inverting input and a non-inverting input and an output; said inverting input receiving one side of said negative impedance port; said non-inverting input receiving a reference voltage; and said output forming, with the other side of said negative impedance port, the output of said improved negative impedance converter.
Claim 3
Dependent Claim
57 words
The improved negative impedance converter of claim 1, said conventional negative impedance converter comprising a second differential operational amplifier having two inputs and an output, wherein one of said two inputs together with the output form said positive impedance port, and wherein said one of said two inputs being said other side of said negative impedance port.
Claim 4
Dependent Claim
44 words
The improved negative impedance converter of claim 2, said inverting inputs of said first and second operational amplifiers being interconnected by first impedance circuit means; said output and said inverting input of said second operational amplifier being interconnected by second impedance circuit means Z3.
Claim 5
Dependent Claim
35 words
The improved negative impedance converter of claim 3, said first differential operational amplifier having its output and its inverting input interconnected with third impedance circuit means Z2 to provide a gain factor of minus one.
Claim 6
Dependent Claim
12 words
The improved negative impedance converter of claim 4, wherein (Z1+Z2)/Z3 equals unity.
Claim 7
Dependent Claim
19 words
The improved negative impedance converter of claim 5, said impedance circuit means Z1, Z2 and Z3 being substantially resistive.
References Cited (Backward Citations)
US2788496A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-23 | 1982-10-23 | 1983-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-23 | 1986-10-23 | 1987-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-23 | 1990-10-23 | 1991-04-24 | $7700.00 | Window Closed / Lapsed |