摘要 |
A ladder filter including a series arm resonator and a parallel arm resonator disposed on the same common piezoelectric substrate achieves improved miniaturization. The ladder filter includes series arm resonators and parallel arm resonators, which include elastic wave resonators, and are disposed on the same common piezoelectric substrate, at least one parallel arm resonator of the series arm resonators and the parallel arm resonators includes a first resonator and a second resonator electrically connected in parallel to each other, and the first resonator and the second resonator are arranged in parallel or substantially in parallel in a direction perpendicular or substantially perpendicular to an elastic wave propagation direction, on one side outside one series arm resonator of remaining resonators in the elastic wave propagation direction thereof.
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