Patent ID: 9197189
Filing Date: 2015-11-24
Classification: H03H

Abstract:
1. An acoustic wave device comprising: a plurality of resonator structures each including a plurality of resonators arranged next to each other, each of the resonator structures being excited in at least two vibration modes as the resonators thereof are coupled and resonate with each other; and two balanced input terminals and/or two balanced output terminals; wherein at least one of the resonator structures has stronger resonance characteristics in one of the vibration modes than in the other vibration mode or modes within a filter band and defines a parallel resonator connected between the two balanced input terminals or between the two balanced output terminals or between one of the two balanced input terminals and one of the two balanced output terminals; each of the resonators of the resonator structures is a piezoelectric thin-film resonator including a pair of electrode films and a piezoelectric thin film located between the pair of electrode films; each of the resonator structures is a stacked bulk acoustic wave device including the piezoelectric thin-film resonators stacked in a direction of lamination of the pair of electrode films and the piezoelectric thin film; and one of the stacked bulk acoustic wave devices is connected in series with another one of the stacked bulk acoustic wave devices on one of an input side or an output side and in parallel with yet another one of the stacked bulk acoustic wave devices on the other of the input side or the output side.