Patent US3621473A successfully refreshed from Google Patents.
US3621473A
Expired / Lapsed
US
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Balanced modulator with jfet{40 s voltage controlled resistors
Assignee: Collins Radio Co
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Filing: 1970-02-03
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Granted: 1971-11-16
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Expires: 1990-02-03
Abstract
Abstract A balanced modulator up-translating an audio input signal to carrier sidebands with the carrier suppressed in the output via two field effect transistors used as voltage controlled resistors in a series shunt configuration.
Inventors
- 👤 C Daniel W Stoffer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:57
CPC Classifications
H; H03; H03D; H03D7/00; H03D7/14; H03D7/1425; H03D7/1441; H03C; H03C1/00; H03C1/52; H03C1/54; H03C1/542; H03C1/547; H03D7/1408; H03D7/1483; H03D7/1491; H03D7/12; H03D7/125
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
208 words
In a balanced modulator circuit for translating a first input signal by a second input signal to a different third signal frequency; two like first and second field effect semiconductor devices each having at least three electrode connections, first, second, and third electrodes; first input signal coupling means connected to the first electrode of said first semiconductor device; connection of the first electrode of said second semiconductor to a voltage potential reference source; second input signal coupling means connected to a primary coil of a transformer; said transformer having a tapped secondary coil with the tap connected to said voltage potential reference source, and with secondary coil opposite ends connected to, respectively, the second electrode connections of said first and second field effect semiconductor devices; with both said third electrode connections connected in common as signal output means; whErein said secondary coil opposite ends are interconnected through capacitive means; said first input signal coupling means provides an audio input path with said first input signal being an audio signal; and with the first electrode of said first semiconductor device connected through an RF coupling capacitor to said voltage potential reference source; and wherein said first and second field effect semiconductor devices are each a junction field effect transistor.
Claim 2
Dependent Claim
208 words
In a balanced modulator circuit for translating a first input signal by a second input signal to a different third signal frequency; two like first and second field effect semiconductor devices each having at least three electrode connections, first, second, and third electrodes; first input signal coupling means connected to the first electrode of said first semiconductor device; connection of the first electrode of said second semiconductor to a voltage potential reference source; second input signal coupling means connected to a primary coil of a transformer; said transformer having a tapped secondary coil with the tap connected to said voltage potential reference source, and with secondary coil opposite ends connected to, respectively, the second electrode connections of said first and second field effect semiconductor devices; with both said third electrode connections connected in common as signal output means; whErein said secondary coil opposite ends are interconnected through capacitive means; said first input signal coupling means provides an audio input path with said first input signal being an audio signal; and with the first electrode of said first semiconductor device connected through an RF coupling capacitor to said voltage potential reference source; and wherein said first and second field effect semiconductor devices are each a junction field effect transistor.
Claim 3
Dependent Claim
34 words
The balanced modulator circuit of claim 1, wherein an audio signal coupling capacitor is included in said first input signal coupling means; and resistive means is connected in parallel with said Rf coupling capacitor.
Claim 4
Dependent Claim
24 words
The balanced modulator circuit of claim 1, with said tapped secondary coil a center-tapped secondary coil; and with said voltage potential reference source ground.
Claim 5
Dependent Claim
45 words
The balanced modulator circuit of claim 3, wherein one end of said transformer primary coil is connected to said second input signal coupling means and the other end of the primary coil is connected to ground; and with the second input signal a carrier signal.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |