ACTIVE BROAD-BAND PIEZOELECTRIC FILTER Russian patent published in 1999 - IPC

FIELD: electronic engineering. SUBSTANCE: filter has two sections identical in structure, each incorporating piezoelectric resonator, as well as first and second negative-feedback operational amplifiers interconnected so that they form inductance simulating converter. Filter also has algebraic adder whose output functions as that of filter. Outputs of first and second sections are connected to first and second inputs of algebraic adder, respectively. Each filter section has, in addition, third capacitor inserted between output of first operational amplifier and noninverting input of second operational amplifier; mentioned piezoelectric resonator is connected in parallel with first capacitor. EFFECT: improved stability and facilitated tuning of filter. 4 dwg