At least corresponding to one which is provided on the surface acoustic wave device null piezoelectric substrate having the surface acoustic wave filter component, the based substrate and

摘要

PROBLEM TO BE SOLVED: To provide a surface acoustic wave device provided with a ladder type surface acoustic wave filter element for increasing an out-band attenuation while suppressing an in-band insertion loss.;SOLUTION: In the surface acoustic wave device comprising the ladder type surface acoustic wave filter element 10 and a base substrate 40 for mountaining the surface acoustic wave filter element 10, the base substrate 40 includes ground extract patterns 43, 44, and a common ground pattern 45 connected to the ground extract patterns 43, 44, and the inductive component of the ground extract patterns 43 differs from that of the ground extract patterns 44. Since this invention can form at least two attenuation poles in an optional frequency band in a cut-off band depending on the differences from the inductive components as above, the surface acoustic wave device can increase the out-band attenuation while suppressing the in-band insertion loss.;COPYRIGHT: (C)2004,JPO