| US 7,567,014 B2 | ||
| Energy trap piezoelectric resonator | ||
| Hitoshi Sakaguchi, Yasu (Japan); Hiroaki Kaida, Moriyama (Japan); and Takashi Hase, Yasu (Japan) | ||
| Assigned to Murata Manufacturing Co., Ltd., Kyoto (Japan) | ||
| Appl. No. 10/559,240 PCT Filed Apr. 20, 2005, PCT No. PCT/JP2005/007501 § 371(c)(1), (2), (4) Date Nov. 30, 2005, PCT Pub. No. WO2006/040851, PCT Pub. Date Apr. 20, 2006. |
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| Claims priority of application No. 2004-300406 (JP), filed on Oct. 14, 2004; and application No. 2005-088657 (JP), filed on Mar. 25, 2005. | ||
| Prior Publication US 2008/0179994 A1, Jul. 31, 2008 | ||
| Int. Cl. H01L 41/047 (2006.01) | ||
| U.S. Cl. 310—320 [310/366] | 11 Claims |
| 1. An energy trap piezoelectric resonator making use of a harmonic wave in a thickness longitudinal vibration mode, comprising:
a piezoelectric substrate having opposing first and second principal surfaces;
a first excitation electrode disposed at the first principal surface of the piezoelectric substrate, and a second excitation
electrode disposed at the second principal surface of the piezoelectric substrate so as to oppose the first excitation electrode,
a portion where the first and second excitation electrodes oppose each other being a piezoelectric vibration portion; and
at least one floating electrode disposed at at least one of the first and second principal surfaces of the piezoelectric substrate
so as to be arranged near the piezoelectric vibration portion and so as to extend towards and away from the first and second
excitation electrodes with respect to a node of an electric potential distribution based on electric charges generated at
the first and second principal surfaces of the piezoelectric substrate by a fundamental wave in a thickness longitudinal vibration
mode; and
the at least one floating electrode includes a vibration damping portion arranged to suppress a fundamental wave in a thickness
longitudinal vibration mode.
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