| 摘要 |
PROBLEM TO BE SOLVED: To provide a piezoelectric resonator for preventing undesired vibration caused by leakage of the vibration, and for suppressing generation of a spurious signal. SOLUTION: The piezoelectric resonator is composed of a lower electrode 3, a piezoelectric material 1, a spurious control layer 16, and an upper electrode 2 each formed in order on a substrate 5 provided with a cavity 4. The spurious control layer 16 for controlling a spurious frequency is formed by a metallic body, a dielectric material, and a piezoelectric material (whose material is different from the piezoelectric material 1 for forming the piezoelectric resonator). By adding the spurious control layer 16, the variation amount in frequency of the spurious signal caused by the undesired vibration can be made larger than the variation amount in frequency of a main resonance of the piezoelectric resonator. Therefore, the piezoelectric resonator having admittance frequency characteristics which do not generate the spurious signal between a resonance frequency fr and an anti-resonance frequency fa can be realized. COPYRIGHT: (C)2005,JPO&NCIPI
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