| 摘要 |
FIELD: radio electronics; communications engineering and measurement technology. ^ SUBSTANCE: proposed rejection filter has N parallel-connected piezoelectric resonators 1 whose first leads functioning as filter input are connected to first lead of first resistor 2, second leads are connected to first lead of second resistor 3 and through third resistor 4, to inverting input of operational amplifier 3; second lead of second resistor 3 is connected to common bus, and output of operational amplifier 5 functions as filter output. Second lead of first resistor 2 is connected to first lead of resistor 6 and through fourth resistor 7, to inverting input of operational amplifier 5; noninverting input of operational amplifier 5 is connected through fifth resistor 8 to common bus. With adequately chosen circuit components at frequencies close to series-resonant frequency of any of N piezoelectric resonators input signals of algebraic adder across operational amplifier 5 will have equal phase and amplitude. Rejection band is attained due to subtraction operation. Signals will be in antiphase at other frequencies and differential signal in two passbands will be amplified. ^ EFFECT: enhanced quantity of rejection bands. ^ 1 cl, 1 dwg |
