PURPOSE: To easily realize devices with various kinds of characteristics and to enable them to be used in a high frequency band area by arranging at least three oscillation electrodes arranged so as to be superposed on a plate shape main body consisting of a piezoelectric material in the thickness direction of the main body.
CONSTITUTION: In a filter device 11, the oscillation electrode 14 is comprised on the lower plane of the main body 12 so as to confront in surface and back with division electrodes 13a and 13b on the plate shape main body 12 consisting of a Pb(Zr, Ti)O3 group piezoelectric material. Also, the oscillation electrode 15 is formed in the main body 12 so as to be superposed on the electrodes 13a and 14, and the electrode 14. And by setting the electrode 13a as an input terminal, the electrode 13b as an output terminal, and using the electrode 14 by connecting to ground potential, the secondary higher harmonic of thickness longitudinal oscillation mode can be confined in piezoelectric ceramic layers 12a and 12b sandwiched by the oscillation electrodes 13-15. Thereby, it is possible to easily realize the devices with a various kinds of characteristics without receiving the constraint of the material characteristic of the main body 12, and also, to easily obtain the device 11 available in the higher harmonic band area.
ANDO AKIRA
TAMURA HIROSHI
| JPS5885614A | 1983-05-23 | |||
| JPS6412609A | 1989-01-17 |
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