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

FIELD: physics, radio.

SUBSTANCE: invention relates to radio engineering and communication and can be used in automatic gain devices, phase detectors and modulators, in phase-locked loop and frequency multiplication systems or as an amplifier whose voltage transfer ratio depends on the control signal level. The controlled amplifier is the basic block of modern systems for receiving and processing high-frequency and microwave signals, and analogue computer and measurement equipment. The complementary differential amplifier (CDA) has a first (1) differential stage (DS) having first (2) and second (3) potential inputs, a current output (4) connected to the first (5) input of an output current adder (6), first (7) reference current source (RCS) connected to the common emitter circuit (8) of the first (1) DS, a second DS (9) having first (10) and second (11) potential inputs connected to corresponding first (2) and second (3) potential inputs of the fist DS (1) and first (12) and second (13) inputs of the CDA, as well as a current output (14) connected to the second (15) input of the output current adder (6), a second (16) RCS connected to the common emitter circuit (17) of the second DS (9). The circuit includes a first additional transistor (T) (18) whose emitter is connected through a first additional resistor (19) to the common emitter circuit (17) of the second DS (9) and the first additional (20) RCS, the base is connected to the first control input (21) of the CDA and the collector is connected to the common emitter circuit (8) of the first DS (1).

EFFECT: lower power supply voltage and electronic voltage gain control.

2 cl, 14 dwg