ELASTIC SURFACE WAVE FILTER DEVICE

摘要

A surface acoustic wave filter device uses a Rayleigh wave as a main mode, and includes a ladder type surface acoustic wave filter unit. A thickness of a dielectric layer in a surface acoustic wave resonator configuring a series arm resonator is different from thickness of a dielectric layer in a surface acoustic wave resonator configuring a parallel arm resonator. A propagation orientation of a surface acoustic wave in the surface acoustic wave resonator configuring the series arm resonator is different from a propagation orientation of a surface acoustic wave in the surface acoustic wave resonator configuring the parallel arm resonator.