摘要 |
A surface acoustic wave element is provided including an IDT and reflectors provided on both sides of the IDT that are on a surface of a quartz plate. The quartz plate is made from an in-plane rotated ST cut quartz plate whose cutting angle is expressed as (0°, 113°-135°, ±(40°-49°)) by defining and using Euler angle. The IDT and reflectors are arranged at a slant of PFA±3° with respect to a direction of a phase velocity of a surface acoustic wave in the quartz plate. If the cutting angle of the quartz plate is expressed by the Euler angle (phi°, theta°, Psi°), the power flow angle PFA is expressed that the PFA=0.374 (theta°-90°)-10.0°.
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