Keating & Bennett, llp
Piezoelectric resonator with electrode radius related to resonator thickness and vibration mode, and filter using the same
A piezoelectric resonator using an nth-order mode of a thickness longitudinal vibration or a thickness-shear vibration includes a vibrating section having a piezoelectric layer, a pair of electrodes and a support member for holding the vibrating section. The pair of electrodes are provided on opposite sides of the piezoelectric layer, respectively, and the pair of electrodes partially overlap with each other via the piezoelectric layer to define an opposite electrode portion. The support member holds the vibrating section such that the vibrating section vibrates under an nth-order mode of a thickness longitudinal vibration or a thickness-shear vibration. The opposite electrode portion preferably has a substantially circular shape having a radius r or is a polygonal shape circumscribing the substantially circular shape. The radius r satisfies the inequality 20t/n&lE;r, where t is a thickness of the vibrating section.
Murata Manufacturing Co., Ltd.
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additional inventional inventional inventional
Masaki Noromitsu Akihiko
Takeuchi Tsukai Shibata