Surface acoustic wave device

摘要

A surface acoustic wave device has a piezoelectric substrate and an IDT formed on the piezoelectric substrate, and uses an excited wave as an SH wave. The piezoelectric substrate is a quartz plate in which a cut angle theta of a rotated Y-cut quartz substrate is set in the range of -65°<=theta<=-51° in a counter-clockwise direction from a crystal Z-axis and the propagation direction of a surface acoustic wave is set in the range (90°±5°) with respect to a crystal X-axis. The IDT is made of Ta or an alloyed metal containing Ta as the main component.