US3702405A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronically variable capacitance
Assignee: United States Department of the Air Force
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Filing: 1971-11-17
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Granted: 1972-11-07
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Expires: 1991-11-17
Abstract
Abstract An electronically controlled capacitor utilizing an analog multiplier and to obtain an effect analogous to the Miller Effect. An input signal is fed through an input resistor which is connected to a fixed capacitor which is in turn coupled to a transistor in a common base configuration. An analog multiplier is capacitively coupled to the transistor''s collector which drives the input side of the fixed capacitor through an output resistor.
Inventors
- 👤 Robert Zwirn
- 👤 Ralph E Johnson
- 👤 Jacob M Sacks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:48
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/46; H03H11/48; H03H11/483
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
76 words
A capacitance control circuit comprising: a. a capacitor having first and second terminals; b. an input resistor connected to the first terminal of the capacitor; c. a transistor having an emitter and collector, the emitter being connected to the second terminal of the capacitor; d. an analog multiplier capacitively coupled to the collector of the transistor; and e. an output resistor connected between the first terminal of the capacitor and the output of the analog multiplier.
Claim 2
Dependent Claim
76 words
A capacitance control circuit comprising: a. a capacitor having first and second terminals; b. an input resistor connected to the first terminal of the capacitor; c. a transistor having an emitter and collector, the emitter being connected to the second terminal of the capacitor; d. an analog multiplier capacitively coupled to the collector of the transistor; and e. an output resistor connected between the first terminal of the capacitor and the output of the analog multiplier.
Claim 3
Dependent Claim
64 words
A capacitance control circuit comprising: a. a mixer having first and second inputs; b. a resistor fed by the output of the mixer; c. an amplifier fed by the output of the resistor; d. a capacitor in shunt with the amplifier; and e. an analog divider fed by the amplifier with the output of the analog divider comprising the second input of the mixer.
Claim 4
Dependent Claim
64 words
A capacitance control circuit comprising: a. a mixer having first and second inputs; b. a resistor fed by the output of the mixer; c. an amplifier fed by the output of the resistor; d. a capacitor in shunt with the amplifier; and e. an analog divider fed by the amplifier with the output of the analog divider comprising the second input of the mixer.
Claim 5
Dependent Claim
20 words
A capacitance control circuit according to claim 2 wherein thE analog divider comprises an operational amplifier and an analog multiplier.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-07 | 1976-05-08 | 1976-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-07 | 1980-05-08 | 1980-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-07 | 1984-05-08 | 1984-11-07 | $7700.00 | Window Closed / Lapsed |