US3605027A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amplifier
Assignee: United States Department of the Navy
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Filing: 1969-02-19
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Granted: 1971-09-14
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Expires: 1989-02-19
Abstract
Abstract A log intermediate-frequency amplifier in which a voltage feedback circuit is used between the output and the input of a summing DC amplifier to provide a substantially low effective input impedance for the DC amplifier to eliminate the error caused by the possibility of back biasing of detector stages comprising part of the composite log amplifier.
Inventors
- 👤 Daniel R Nichols
- 👤 John O Wedel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:49
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/24
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
144 words
A log IF amplifier comprising: a. a plurality of cascaded AM-IF amplifier-limiter stages; b. a detector stage for each amplifier-limiter stage, each said detector stage including a forward biased semiconductor diode, a resistor and a capacitor series connected between the output circuit of its associated amplifier-limiter stage and ground; c. a DC amplifier; d. a summing line including a plurality of inductors, individual inductors of the summing line interconnecting resistorcapacitor junctions of adjacent detector stages to one another and to the DC amplifier; e. and a feedback network comprising a resistor connected between the input and output of the DC amplifier whereby the effective input resistance to said DC amplifier is of a substantially low value to prevent the large detected signal from the last amplifier stage from feeding back along the summing line to back bias the diodes of the remaining detector stages.
Claim 2
Dependent Claim
144 words
A log IF amplifier comprising: a. a plurality of cascaded AM-IF amplifier-limiter stages; b. a detector stage for each amplifier-limiter stage, each said detector stage including a forward biased semiconductor diode, a resistor and a capacitor series connected between the output circuit of its associated amplifier-limiter stage and ground; c. a DC amplifier; d. a summing line including a plurality of inductors, individual inductors of the summing line interconnecting resistorcapacitor junctions of adjacent detector stages to one another and to the DC amplifier; e. and a feedback network comprising a resistor connected between the input and output of the DC amplifier whereby the effective input resistance to said DC amplifier is of a substantially low value to prevent the large detected signal from the last amplifier stage from feeding back along the summing line to back bias the diodes of the remaining detector stages.
Claim 3
Dependent Claim
92 words
A log IF amplifier substantially as described in claim 5 wherein: a. the resistance value of the resistors of the detector stages are equal; b. and wherein the forward gain of the DC amplifier is substantially larger than the ratio of the resistance of the feedback resistor and a detector stage resistor, and the closed-loop gain of said DC amplifier is unity, whereby the effective input impedance to said DC amplifier is approximately equal to the ratio of the resistance of the feedback resistor and the forward gain of said DC amplifier.
References Cited (Backward Citations)
US2577506A
Cited
US2729743A
Cited
US3403347A
Cited
US3371224A
Cited
US3435353A
Cited
US3480793A
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 |