ACTIVE PIEZOELECTRIC FILTER Russian patent published in 2001 - IPC

FIELD: radio electronics. SUBSTANCE: given active piezoelectric filter can be used in radio receivers and in measurement technology in the capacity of filter with several bandwidths. Filter includes algebraic adder 1 built on operational amplifier 2, output of adder 1 being output of filter, first and second piezoresonators 6, 7 whose first leads-out are connected to input terminal of filter, whose second leads-out are connected via resistors 8, 9 to inputs of first and second inverters built on operational amplifiers 10, 11. Outputs of operational amplifiers 10, 11 are connected to first and second inputs of adder 1. Double-pole circuits 12, 13 made of piezoresonators and resistors connected in series are placed between input of filter and inputs of inverters. EFFECT: filter provides for several bandwidths. 2 dwg