CASCODE DIFFERENTIAL AMPLIFIER WITH CONTROLLED AMPLIFICATION Russian patent published in 2010 - IPC H03F3/45 H03G3/30 

FIELD: radio engineering.

SUBSTANCE: invention may be used in devices of automatic adjustment of amplification, phase detectors and modulators, and also in systems of phase self-tuning and multiplication of frequency or as amplifier, voltage transfer coefficient of which depends on the level of control signal. Controlled amplifier is the basic unit of up-to-date systems for receiving and processing of signals from HF and SHF ranges, analog computer and metering equipment. Cascode differential amplifier (CDA) with controlled amplification comprises the first (1) and second (2) input transistors, emitters of which are connected to source of reference current (3). The first (4) and second (5) output composite transistors, main emitters of which (6, 7) are connected to according collectors of the first (1) and second (2) input transistors, collectors are joined by load circuit (8), and bases are connected to source of shift voltage source (9). Circuit includes additional transistor (10), emitter of which is connected to additional source of reference current (11) and via additional resistor (12) is connected to combined emitters of the first (1) and second (2) input transistors. Base is connected to control input (13) of CDA with controlled amplification, besides as the first (3) and second (4) of output composite transistors, composite transistors are used with the main (6, 7) and additional (14, 15) emitters, which are combined to each other and joined to collector of additional transistor (10).

EFFECT: reduced supply voltage, expansion of functional possibilities of amplifier as mixer.

5 cl, 13 dwg