BAND-PASS FILTER ON TWO OPERATIONAL AMPLIFIERS WITH INDEPENDENT ADJUSTMENT OF MAIN PARAMETERS Russian patent published in 2019 - IPC H03H11/12 

FIELD: physics.

SUBSTANCE: invention relates to means of extracting a predetermined spectrum of a signal source, e.g. during further processing by analogue-to-digital converters of various modifications. Band-pass filter contains two differential operational amplifiers, resistors and capacitors. Frequency of pole ω_p, at which phase shift is -180°, is changed due to second 5 and third 6 resistors (R5 and R6) in relatively wide range, when the resistances of first 4 (R4), fifth 9 (R9) and eighth 12 (R12) resistors change, the PFC inclination changes within the frequency of the pole and the AFC rise at that frequency changes. At that, pole frequency remains invariable (ω_p=const). When adjusting pole attenuation frequencies are varied, at which phase shift is -135° and -225°. To obtain the specified transmission coefficient M at the central frequency, resistance of fourth 8 (R8) resistor is changed.

EFFECT: technical result consists in providing independent adjustment of three main parameters AFC – frequency of pole (ω_p), pole attenuation (d_p), as well as transmission coefficient in pass band (M).

1 cl, 6 dwg