SURFACE ACOUSTIC WAVE APPARATUS

摘要

A surface acoustic wave apparatus capable of obtaining better resonance characteristic and filter characteristic because the formation of an SiO2 film allows an improvement in a frequency-temperature characteristic, the prevention of an increase in an insertion loss, the acquisition of the reflection coefficient of an electrode with a sufficient size, and further the suppression of undesired spurious is provided. The surface acoustic wave apparatus (11) in which a plurality of grooves (1b) are formed on an upper surface (1a) of an LiNbO3 substrate (1), an IDT electrode (3) based on a Pt is formed in the grooves (1b), the SiO2 layer (4) is formed so as to cover the upper surface (1a) of the LiNbO3 substrate (1) and the IDT electrode (3), and the surface of the SiO2 layer (4) is smoothed and which utilizes a Rayleigh wave response and in which the Euler angle of the LiNbO3 substrate is in the range of (0° ±5°, 208° to 228°, 0° ±5°).