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EP0336191A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Circuitry for making a differential output single-ended

Assignee: Nokia Oyj
•
Filing: 1989-03-20
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Granted: —
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Expires: 2009-03-20
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Abstract

Abstract This invention relates to balanced mixers with respect to their output stages, by making the differential mixer out­put (A, B) a single-ended output (C) without a matching transformer. To that purpose, a transistor current mirror is used in which, the collector of each current mirror transistor (Tr1, Tr2) is coupled to one of the two branches (A, B) of the differential output of the mixer and the output (C) of the current mirror is the collector of the current mirror transistor (Tr2) coupled as an amplifier. The circuitry can be used in all balanced transistor mixers, provided that both sides of the differ­ential output are available for use.

Inventors

  • 👤 Jouni Nyqvist

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-06 10:08
CPC Classifications
H; H03; H03D; H03D7/00; H03D7/14; H03D7/1425; H03D7/1433; H03D7/1458; H03D2200/00; H03D2200/0001; H03D2200/0033; H03D2200/0041; H03D2200/0088

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 83 words
A circuitry by means of which the differential outputs (A, B) of a balanced mixer are converted into a single-­ended output (C), characterized in that the circuitry is made up of a transistor current mirror, the collector of each current mirror transistor (Tr1, Tr2) being coupled to one of the two branches (A, B) of the differential output of the mixer and the output (C) of the current mirror being on the collector of the current mirror transistor (Tr2) coupled as an amplifier.
Claim 2
Dependent Claim 83 words
A circuitry by means of which the differential outputs (A, B) of a balanced mixer are converted into a single-­ended output (C), characterized in that the circuitry is made up of a transistor current mirror, the collector of each current mirror transistor (Tr1, Tr2) being coupled to one of the two branches (A, B) of the differential output of the mixer and the output (C) of the current mirror being on the collector of the current mirror transistor (Tr2) coupled as an amplifier.
Claim 3
Dependent Claim 37 words
A circuitry according to Claim 1, characterized in that the collectors of the current mirror transistors (Tr1, Tr2) are coupled directly to the collectors of the output transistors (Tr3-Tr6) of the mixer, without matching resis­tors in between.
Claim 4
Dependent Claim 74 words
A circuitry according to Claim 1 or 2, characterized in that the current mirror transistors (Tr1, Tr2) and the resistors (R3, R5) coupled in parallel to these transistors from the output impedance matching resistors (R3, R4, R5) of the current mirror have been selected so that the volt­age losses (Vco) caused by collector currents in these resistors (R3, R5) coupled in parallel are greater than the base-emitter voltage (Vbe) of the current mirror transis­tors.
Claim 5
Dependent Claim 39 words
A circuitry according to any of the above claims, characterized in that matching resistors (R1, R2) are coupled in series to the emitters of the current mirror transistors (Tr1, Tr2) in order to match these transistors to each other.

References Cited (Backward Citations)

GB2018070A Cited
EP0073929A2 Cited

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