The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 25, 2000
Filed:
Apr. 10, 1998
Masaya Wajima, Sinminato, JP;
Jiro Inoue, Omihachiman, JP;
Hiroaki Kaida, Moriyama, JP;
Mitsuhiro Yamada, Shiga-ken, JP;
Abstract
An energy-trapping piezoelectric resonator vibrates in a third-order wave of a thickness-extension vibration mode. The piezoelectric resonator includes a piezoelectric substrate polarized along its thickness. A ratio of the width W to the thickness T of the substrate is determined to be about 0.88.+-.5%, 1.06.+-.4%, 1.32.+-.5%, 1.80.+-.3%, 2.30.+-.3%, 2.69.+-.3%, 3.16.+-.2%, or 3.64.+-.2%. First and second electrodes are respectively disposed on the obverse and reverse surfaces of the substrate to cover the entire width and opposedly face each other at the central portion of the substrate in the longitudinal direction so as to form a resonance portion between the first and second electrodes. It is thus possible to obtain a piezoelectric resonator which does not require a large extra area of the substrate around the resonance portion and which exhibits good resonance characteristics by effectively suppressing unwanted spurious responses in a range between and near the resonant frequency and the anti-resonant frequency.