SELECTIVE AMPLIFIER WITH EXTENDED FREQUENCY BAND Russian patent published in 2014 - IPC H03F3/00 

FIELD: radio engineering, communication.

SUBSTANCE: device includes a main operational amplifier, between the output and the inverting input of which a first frequency-dependent resistor is connected, first and second frequency-setting capacitors connected in series between the output of the main operational amplifier and its inverting input, a second frequency-setting resistor, the first lead of which is connected to the common node of the series-connected frequency-setting capacitors, an input voltage source, first and second power supply buses; the second frequency-setting resistor is connected between the common node of the first and second frequency-setting capacitors and the first power supply bus; the input voltage source is connected to the inverting input of an additional voltage-to-current converter, the non-inverting input of which is connected to the inverting input of the main operational amplifier; the common emitter circuit of the additional voltage-to-current converter is connected to the second power supply bus, and the current output of the additional voltage-to-current converter is connected to the common node of the frequency-setting capacitors.

EFFECT: wider frequency band of the selective amplifier by reducing the effect of gain-crossover frequency f₁ of the main operational amplifier on the quasi-resonance frequency f₀.

15 dwg