Patent ID: 8598766

Claim:
A surface acoustic wave resonator comprising: a quartz crystal substrate with Euler angles (−1.5°≦φ≦1.5°, 117°≦θ≦142°, and 42.79°≦|Ψ|≦49.57°); and an IDT that is provided on the quartz crystal substrate, includes a plurality of electrode fingers, and excites a stop band upper end mode surface acoustic wave, wherein inter-electrode finger grooves which are depressions of the quartz crystal substrate are provided between the electrode fingers in a plan view, and wherein if a line occupation rate of convex portions of the quartz crystal substrate disposed between the inter-electrode finger grooves is ηg, and a line occupation rate of the electrode fingers disposed on the convex portions is ηe, the following relationships are satisfied in a case where an effective line occupation rate ηeff of the IDT is an arithmetic mean of the line occupation rate ηg and the line occupation rate ηe η g >η e 0.59<η eff <0.73.