Patent ID: 9748920
Date: 2017-08-29
CPC Classifications: H03H

Claim:
1. A resonator element comprising: a vibrating portion that vibrates in a thickness shear vibration and includes a first main surface and a second main surface which are in a front and back relationship to each other; a first excitation electrode that is provided on the first main surface; and a second excitation electrode that is provided on the second main surface, wherein an energy trapping coefficient M, a frequency decrease amount Δ, a cut-off frequency fs, and a frequency fe satisfy relationships of where M is an energy trapping coefficient, K is an anisotropy coefficient of the vibrating portion, hx is a length along the thickness shear vibration direction of the first excitation electrode and the second excitation electrode, is is a thickness of the vibrating portion, Δ is a frequency decrease amount, fs is a cut-off frequency of the vibrating portion, fe is a frequency when the first excitation electrode and the second excitation electrode are disposed in the vibrating portion, R is a frequency integer of the vibrating portion, te is a sum of the thicknesses of the first excitation electrode and the second excitation electrode, ρe is densities of the first excitation electrode and the second excitation electrode, and ρx is a density of the vibrating portion.