SURFACE ACOUSTIC WAVE DEVICE

摘要

[PROBLEMS] To provide a means for improving a Q value of an SAW device which uses SH wave type surface acoustic wave. [MEANS FOR SOLVING PROBLEMS] A rotated Y-cut crystal substrate has a cut angle (?) satisfying an inequality of -64.0°<?<-49.3° in a counterclockwise direction from a Z axis. In the surface acoustic wave device, at least one IDT electrode is arranged along a vertical direction (Z' axis direction) of a crystal axis (X) of the crystal substrate, and grating reflectors are arranged on the both sides. A film thickness (H) of the electrode is standardized by an electrode cycle (?) of the IDT electrode to satisfy an inequality of 0.04<H/?<0.12. When a crossing width of the IDT electrode is expressed as (W), the standardized crossing width W/? standardized by the electrode cycle (?) of the IDT electrode satisfies an inequality of 20=W/?=50.