Surface acoustic wave resonator, surface acoustic wave oscillator, and electronic apparatus

摘要

A surface acoustic wave resonator includes a quartz substrate with preselected Euler angles and an IDT on the quartz substrate. The IDT includes electrode fingers and excites a stop band upper end mode surface acoustic wave. Inter-electrode finger grooves are provided between the electrode fingers. Assuming a surface acoustic wave wavelength is λ, an electrode finger film thickness is H, an inter-electrode finger groove depth is G, a line occupation rate of convex portions of the substrate between the inter-electrode finger grooves is ηg, and a line occupation rate of the electrode fingers on the convex portions is ηe, 0.0407λ≦G+H; and ηg>ηe.

主权项

1. 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°); an IDT that is provided on the quartz crystal substrate, that includes a plurality of electrode fingers, and that excites a stop band upper end mode surface acoustic wave; and inter-electrode finger grooves that are provided in the quartz crystal substrate between the electrode fingers in a plan view, wherein when a wavelength of the surface acoustic wave is λ, a first film thickness of the electrode finger is H, and a first depth of the inter-electrode finger groove is G, and when 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:
0.0407λ≦G+H; andηg>ηe.