SELECTIVE AMPLIFIER Russian patent published in 2013 - IPC H03F3/00 

FIELD: radio engineering, communication.

SUBSTANCE: selective amplifier comprises the first and second input transistors, a source of auxiliary voltage, the first and second sources of reference current, the first bus of a supply source, the third and fourth input transistors, the third source of reference current, the first frequency-setting resistor, the second bus of a supply source, an additional transistor, a load resistor, the first and second frequency-setting capacitors and the second frequency-setting resistor.

EFFECT: improved quality factor of an amplifier and its amplification ratio by voltage at quasi-resonance frequency f₀.

2 cl, 4 dwg