Patent ID: 11012048

Abstract:
A filter includes: a piezoelectric substrate; a first acoustic wave resonator located on the piezoelectric substrate and including a pair of first reflectors including first grating electrodes and a pair of first comb-shaped electrodes that is located between the first reflectors and includes first electrode fingers; and a second acoustic wave resonator that is connected in series or parallel with the first acoustic wave resonator, is located on the piezoelectric substrate, and includes a pair of second reflectors including second grating electrodes and a pair of second comb-shaped electrodes that is located between the second reflectors and includes second electrode fingers, an average value of duty ratios of the second grating electrodes being different from an average value of duty ratios of the first grating electrodes, an average value of pitches of the second electrode fingers being substantially equal to an average value of pitches of the first electrode fingers.