US4257006A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrable analog active filter and method of same
Assignee: University of Minnesota System
•
Filing: 1979-01-25
•
Granted: 1981-03-17
•
Expires: 1999-01-25
Abstract
Abstract Integrable analog active filter suitable for MOS monolithic implementation. The filter utilizes only integrating amplifiers and ratioed capacitors thus being implementable in MOS technology and compatible for use in MOS digital systems. Filters of unlimited complexity and having arbitrary transfer functions can be implemented by the integrable analog active filter.
Inventors
- 👤 Rolf Schaumann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:58
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/12; H03H11/1217
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
55 words
An active analog filter consisting, essentially, in combination; input and output terminals adapted for connection to a source of signal and signal utilization means; and integrating means effectively free of resistors in performing the integrating operation interconnecting said input and output terminals, said integrating means including amplifier means and reactance means exhibiting resistorless capacitance characteristics.
Claim 2
Dependent Claim
55 words
An active analog filter consisting, essentially, in combination; input and output terminals adapted for connection to a source of signal and signal utilization means; and integrating means effectively free of resistors in performing the integrating operation interconnecting said input and output terminals, said integrating means including amplifier means and reactance means exhibiting resistorless capacitance characteristics.
Claim 3
Dependent Claim
19 words
The subject matter of claim 1 in which the reactance means includes a plurality of capacitors having interrelated values.
Claim 4
Dependent Claim
48 words
The subject matter of claim 1 in which further reactance means and signal combining means are connected intermediate the input terminal and said amplifier means and further reactance means are connected intermediate the output terminal and said signal combining means, all of said reactance means having interrelated magnitudes.
Claim 5
Dependent Claim
37 words
The subject matter of claim 3 in which the integrating means includes at least a pair of amplifier means and each of said amplifier means is connected to said signal combining means through a further reactance means.
Claim 6
Independent Claim
75 words
The method of processing predetermined frequency components of an analog signal comprising the steps of; providing a plurality of reactance means exhibiting resistorless capacitive characteristics; providing a signal combining means; providing a signal integrating means effectively free of resistors in performing the integrating operation; passing a signal through one of said reactance means, said signal combining means and said integrating means while simultaneously passing a signal from said integrating means to said signal combining means.
Claim 7
Independent Claim
75 words
The method of processing predetermined frequency components of an analog signal comprising the steps of; providing a plurality of reactance means exhibiting resistorless capacitive characteristics; providing a signal combining means; providing a signal integrating means effectively free of resistors in performing the integrating operation; passing a signal through one of said reactance means, said signal combining means and said integrating means while simultaneously passing a signal from said integrating means to said signal combining means.
Claim 8
Dependent Claim
16 words
The method of claim 5 in which the reactance means are selected to have interrelated magnitudes.
Claim 9
Dependent Claim
17 words
The method of claim 6 in which the signal is passed through a plurality of integrating means.
Claim 10
Dependent Claim
18 words
The method of claim 7 in which the signal is passed through a successive plurality of integrating means.
References Cited (Backward Citations)
US3401352A
Cited
US3643173A
Cited
US3805178A
Cited
US3904978A
Cited
US3946328A
Cited
US4001712A
Cited
US4156853A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |