SURFACE ACOUSTIC WAVE RESONATOR, SURFACE ACOUSTIC WAVE OSCILLATOR, AND ELECTRONIC DEVICE

Japanese Patent JP2015029358

A

PROBLEM TO BE SOLVED: To provide a surface acoustic wave resonator excellent in oscillation stability regardless of the use environment and a surface acoustic wave oscillator and an electronic device equipped with the resonator.SOLUTION: A SAW resonator 10 comprises: an IDT 12 for exciting a SAW; a pair of reflectors 20 for sandwiching the IDT; and a groove 32 for hollowing a crystal substrate 30 between electrode fingers 18. The crystal substrate 30 with Euler angles (-1.5°≤φ≤1.5°, 117°≤θ≤142°, 42.79°≤|ψ|≤49.57°) is used. When the wavelength of the SAW is defined as λ and the depth of the groove 32 is defined as G, 0.01λ≤G is satisfied. When the line occupancy ratio of IDT 12 is defined as η, the depth of the groove 32, G and the line occupancy ratio, η satisfy the relationships: -2×G/λ+0.72≤η≤-2.5×G/λ+0.7775 (where, 0.01λ≤G≤0.05λ), and -3.5898×G/λ+0.7995≤η≤-2.5×G/λ+0.7775 (where, 0.05λ