| 摘要 |
PURPOSE:To improve the selectivity characteristic in the low band side of the piezoelectric vibrator of the bending vibrating mode, by subjecting the vibrator to polarization processings in directions different from one another. CONSTITUTION:A piezoelectric vibrator has piezoelectric element plate 11, parallel electrodes 14 and 15 formed on one main surface of plate 11, and common electrode 16 formed on the other main surface. Parts of piezoelectric element plate 11 corresponding to parallel electrodes 14 and 15 are subjected to polarization processings in directions different from each other. Thus, an attenuation pole is formed in the low band side in respect to the frequency characteristic. Consequently, the selectivity characteristic in the low band side can be improved considerably. |
