| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a surface acoustic wave filter device which has steep filter characteristics and a wide pass band, and in which a ripple within a pass band is suppressed.SOLUTION: A surface acoustic wave filter device 1 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 series arm resonators S1, S2, S3 is different from a thickness of a dielectric layer in a surface acoustic wave resonator configuring parallel arm resonators P1, P2, P3. A propagation orientation of a surface acoustic wave in the surface acoustic wave resonator configuring the series arm resonators is different from a propagation orientation of a surface acoustic wave in the surface acoustic wave resonator configuring the parallel arm resonators.</p> |
