US3665508A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear double balanced diode mixer
Assignee: General Electric Co
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Filing: 1971-01-04
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Granted: 1972-05-23
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Expires: 1991-01-04
Abstract
Abstract An improved double balanced diode mixer for high frequency operation is described. The mixer contains two series connected pairs of high frequency diodes operated in a modified bridge configuration. The diode series pairs are alternately switched on and off by a local source of high frequency oscillations. The high frequency signal being mixed is applied across the interconnections between the diodes in each series pair. An IF output signal resulting from the mixing process is derived at the output. Mutual isolation is provided between the diode series pairs in their coupling to the local source so that current flowing in one pair produces a minimum effect upon current flowing in the other pair. This provision generally lessens the adverse effects of the charge storage and other diode parasitics at high operating frequencies. The mixer is relatively free of spurious responses and undesired intermodulation products in the IF pass band and is suitable for use in a television receiver.
Inventors
- 👤 Glenn B Gawler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:11
CPC Classifications
H; H03; H03D; H03D7/00; H03D7/14; H03D7/1408
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
234 words
A linear double balanced diode mixer for high frequency operation comprising: A. a first pair of high frequency diodes connected in the same polarity in a series circuit, b. a second pair of high frequency diodes connected in the same polarity in a series circuit, c. a local source of high frequency oscillations of suitable amplitude for switching said diode pairs between nonconduction and forward conduction, d. means balanced to ground for coupling said local source to said first diode pair to achieve forward conduction during positive half cycles of said source and to said second diode pair to achieve forward conduction during negative half cycles of said source, said coupling means coupling said diode pairs in mutual isolation so that current flowing from said local source through one diode pair has a minimum effect upon current flowing from said source through the other diode pair, e. a second source of high frequency signals to be mixed with said local source, f. an RF transformer for applying signals from said second source to said two diode pairs, said transformer having a center tapped secondary, one end terminal being connected to the interconnection between diodes of said first pair and the other end terminal being connected to the interconnection between diodes of said second pair, and g. means connected between said center tap and ground for deriving an intermediate frequency output signal from said mixer.
Claim 2
Dependent Claim
234 words
A linear double balanced diode mixer for high frequency operation comprising: A. a first pair of high frequency diodes connected in the same polarity in a series circuit, b. a second pair of high frequency diodes connected in the same polarity in a series circuit, c. a local source of high frequency oscillations of suitable amplitude for switching said diode pairs between nonconduction and forward conduction, d. means balanced to ground for coupling said local source to said first diode pair to achieve forward conduction during positive half cycles of said source and to said second diode pair to achieve forward conduction during negative half cycles of said source, said coupling means coupling said diode pairs in mutual isolation so that current flowing from said local source through one diode pair has a minimum effect upon current flowing from said source through the other diode pair, e. a second source of high frequency signals to be mixed with said local source, f. an RF transformer for applying signals from said second source to said two diode pairs, said transformer having a center tapped secondary, one end terminal being connected to the interconnection between diodes of said first pair and the other end terminal being connected to the interconnection between diodes of said second pair, and g. means connected between said center tap and ground for deriving an intermediate frequency output signal from said mixer.
Claim 3
Dependent Claim
61 words
A linear double balanced diode mixer as set forth in claim 1 wherein said local source provides oscillations of large amplitude relative to those provided by said second source to said diode pairs so that said diodes are driven well past the ''''knee'''' of their conduction characteristics by said local source and exhibit an essentially linear characteristic to said second source.
Claim 4
Dependent Claim
17 words
A linear double balanced diode mixer as in claim 2 wherein said diodes are hot carrier diodes.
Claim 5
Dependent Claim
64 words
A linear double balanced mixer as set forth in claim 2 wherein said isolative coupling means comprise a first RF transformer of low leakage inductance for coupling said local source to said first diode pair and a second RF transformer of low leakage inductance for coupling said local source to said second diode pair, electrical isolation being provided in part by said leakage inductances.
Claim 6
Dependent Claim
61 words
A linear double balanced mixer as set forth in claim 2 wherein said first RF transformer of said coupling means has a pair of series aiding windings connected in series across said first series diode circuit and said second RF transformer of said coupling means has a pair of series aiding windings connected in series across said second series diode circuit.
Claim 7
Dependent Claim
25 words
A linear double balanced mixer as set forth in claim 5 wherein said RF transformer for said second source is of low leakage inductance design.
Claim 8
Dependent Claim
30 words
A linear double balanced mixer as set forth in claim 5 wherein said first and second RF transformers of said coupling means are trifilarly wound to achieve minimum leakage inductance.
Claim 9
Dependent Claim
51 words
A linear double balanced mixer as set forth in claim 5 wherein said three RF transformers are each trifilarly wound upon a toroidal core to achieve minimum leakage inductance, said core providing a primarily resistive component at the intended frequency of operation so that the magnetization impedances thereof are primarily resistive.
Claim 10
Dependent Claim
54 words
A linear double balanced mixer as set forth in claim 5 wherein said first and second RF transformers are autotransformers, each trifilarly wound upon a toroidal core to achieve minimum leakage inductance, said core providing a primarily resistive component at the intended frequency of operation so that the magnetization impedances thereof are primarily resistive.
References Cited (Backward Citations)
US2550524A
Cited
US3579116A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |