发明名称 |
Piezoelectric resonator, method of manufacturing piezoelectric resonator, and filter, duplexer, and communication device using piezoelectric resonator |
摘要 |
A piezoeletric resonator includes: a substrate (105); a lower electrode (103) formed on or above the substrate; a piezoeletric body (101) formed on or above the lower electrode; an upper electrode (102) formed on or above the piezoeletric body; and a cavity (104) under a vibrating portion formed by the lower electrode, the piezoeletric body, and the upper electrode. Where a resonant frequency of vibration with a thickness of the vibrating portion being a half of a wavelength is taken as fr, an average of ultrasonic velocity in a material forming the cavity is taken as Vc, and a value determined based on the resonant frequency fr and the average of ultrasonic velocity Vc is taken as lambda c (=Vc/fr), a depth of the cavity is set so as to be equal to or larger than nx lambda c/2- lambda c/8 and equal to or smaller than nx lambda c/2+ lambda c/8. <IMAGE> |
申请公布号 |
EP1530292(A2) |
申请公布日期 |
2005.05.11 |
申请号 |
EP20040026163 |
申请日期 |
2004.11.04 |
申请人 |
MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD. |
发明人 |
NAKATSUKA, HIROSHI;ONISHI, KEIJI;NAKAMURA, HIROYUKI;YAMAKAWA, TAKEHIKO;YAMAGUCHI, HIROSHI |
分类号 |
H03H9/15;H03H3/04;H03H9/02;H03H9/17;H03H9/56;(IPC1-7):H03H9/56 |
主分类号 |
H03H9/15 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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