SURFACE-ACOUSTIC WAVE DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a method of reducing a frequency shift at the time of electrifying a SAW device using an SH wave.

SOLUTION: A crystal substrate 11 is made of a substrate for exciting an SH wave type surface wave propagating in the 90°±5° direction with respect to a crystal axis direction (in the Z' axis direction) with a rotation angle θ of a Y cut crystal substrate as about -50° with respect to a crystal axis Z in a counterclockwise direction. An IDT electrode 12 mainly made of aluminum or an aluminum-based alloy is disposed along the Z' axis direction of the crystal substrate 11, and grating reflectors 13a, 13b are disposed at both sides of the crystal substrate 11, thereby constituting an SH wave type surface acoustic wave resonator. When a line pulse duty factor mr is defined by an electrode finger width of an electrode finger constituting the IDT electrode/(the electrode finger width + a space between electrode fingers), the line pulse duty factor mr satisfies 0.41COPYRIGHT: (C)2009,JPO&INPIT