Low insertion loss piezoelectric acoustic bandpass filter and method of realization

摘要

A piezoelectric acoustic bandpass filter with low insertion loss and a realization method. The realization method includes a step of configuring one series branch with one first type piezoelectric acoustic resonator, and a step of configuring one parallel branch having a ground end with one second type piezoelectric acoustic resonator. Connecting one end of each of the series branches to a non-grounded end of the parallel branch to form one acoustic bandpass filter unit, and cascading a plurality of the acoustic bandpass filter units. The impedance value at the series resonance frequency of the first type piezoelectric acoustic resonator is smaller than the impedance value at the series resonance frequency of the second type piezoelectric acoustic resonator. The impedance value at the parallel resonance frequency is smaller than the impedance value at the parallel resonance frequency of the second type piezoelectric acoustic resonator. [Selection] Figure 6