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

FIELD: radio electronics, frequency selection of signals. SUBSTANCE: active band-pass piezoelectric filter has first and second piezoresonators 11, 12, first and second capacitors 7, 6, first transistor 1 to which base first leads of first and second resistors 4, 3 are connected and first leads of third and fourth resistors 9, 8 correspondingly are connected to collector and emitter. Second leads of first and third resistors are tied up together and connected to supply bus and first lead of first capacitor 7 whose second lead is connected to common bus, first lead of fifth resistor 13 is connected to first leads of first and second piezoresistors 11, 12 and second lead of fifth resistor 13 is connected to common bus. First lead of second capacitor 6 is connected to input potential terminal of filter and its second lead is connected to base of first transistor 1. Second transistor 2 of opposite conductance is inserted and second lead of second resistor 3 and first lead of sixth resistor 5 are connected to its base, second lead of sixth resistor 5 is connected to common bus. Second lead of fourth resistor 8 is connected to emitter of second transistor 2 and collector is connected to second lead of second piezoresonator 12 and via seventh resistor 10 to common bus. First lead of piezoresonator 12 is connected to output potential terminal of filter. EFFECT: improved linearity of filter with preservation of its key parameters. 1 dwg