| 摘要 |
PURPOSE:To obtain a crystal resonator with excellent frequency temperature characteristic by applying the theoretical analysis as to a combined crystal resonator where the bending mode and the twist mode oscillation are combined. CONSTITUTION:The relation among a resonance frequency (f) obtained from the combination of the bending mode and the twist mode, a resonance frequency fF of the bending mode and a resonance frequency fT of the twist mode is expressed in Equation (1). The primary - ternary temperature coefficients are obtained by the Taylor expansion of the resonance frequency (f), resulting that a cut angle where both the primary temperature coefficient alpha and the secondary temperature coefficient beta are both zero even at a cut angle of nearly -50 deg. exists. Although the cut angle is varied slightly with the size of the resonator or the like, both alpha and beta are zero at the cut angle within the range between -40 deg. and -60 deg.. |
