| 摘要 |
PURPOSE:To operate the titled transfilter in the frequency band of 1MHz or higher, and to obtain excellent resonant response by using thickness longitudinal vibration and utilizing an energy confining phenomenon. CONSTITUTION:The titled transfilter consists of a low impedance section where there are seven energy confining electrodes 41, 41' at the left side of a piezoelectric ceramic board 40' and a high impedance section where there are three energy confining electrodes 42, 42' at the right side. The electrodes 41 are all connected to a terminal 50 and the electrodes 41' to a terminal 50'. The electrodes 42 are connected to a terminal 51 and the electrode 42' to a terminal 51'. All of the directions of polarization and the directions of electric fields take either of the same phase or antiphase. Accordingly, a half wave-length mode is excited to board thickness, and fundamental thickness longitudinal vibration is excited the most intensely. |
