KT cut width-extensional mode quartz crystal resonator

A width-extensional mode quartz crystal resonator comprising:

• a vibrational potion capable of undergoing a width-extensional mode vibration and being connected to a first frame portion formed integrally by an etching process for supporting the vibrational portion such as to surround the vibrational portion through respective bridge portions arranged at lengthwise opposite ends of the vibrational portion, the first frame portion being connected to a second frame portion through respective ones of the bridge portions arranged near the central portion of the first frame portion, the second frame portion being extended to a mount portion, the vibration portion having a thickness-to-width ratio R.sub.zx in the range of 0.45 through 0.65, and the resonator having a cut angle .phi. in the range of 23.degree. through 28.degree.;
• and excitation electrodes arranged on both top and bottom surfaces of the vibrational portion and perpendicular to the x-axis, the excitation electrodes extending to the mount portion via a respective bridge portion, and each excitation electrode forming a respective terminal electrode.

A width-extensional mode quartz crystal resonator, comprising:

• a quartz crystal piece capable of undergoing a width-extensional mode vibration and having a thickness dimension and a width dimension and a thickness-to-width ratio between 0.45 and 0.65, the quartz crystal piece being formed from a quartz crystal plate cut along a plane defined by rotation a Z plane perpendicular to an optical axis of the quartz crystal around an electrical axis thereof by a rotation angle between 23.degree.-28.degree..