ACTIVE BAND-PASS PIEZOELECTRIC FILTER Russian patent published in 2001 - IPC

FIELD: radio electronics, frequency selection of signal of radio frequencies. SUBSTANCE: active band-pass piezoelectric filter includes first and second operational amplifiers 1 and 2 correspondingly in non-inverting and inverting connection whose corresponding inputs are coupled to source of input signal and whose outputs are connected to inputs of adder built on three resistors 3, 4, 5, its output being output of filter. First capacitor 6 is placed between inverting input of operational amplifier 1 and common bus. Second capacitor 7 is interposed in circuit of positive feedback of second operational amplifier 2. First piezoresonator 11 is inserted between non-inverting input of first operational amplifier and common bus, second piezoresonator 12 is placed in circuit of negative feedback of second operational amplifier. Resistor 13 in inserted in circuit of operational amplifier 1. EFFECT: expanded bandwidth. 1 dwg