| 摘要 |
<P>PROBLEM TO BE SOLVED: To easily obtain excellent filter characteristics. <P>SOLUTION: On a bare chip 10 constituting a ladder type piezoelectric filter 1, parallel arm resonators 101 and 103 are formed on the side of a region 185 between regions 185 and 186 formed by dividing a continuous piezoelectric thin film 15 by a straight line 181, and a series arm resonator 102 is formed on the side of the region 186. Thus, the parallel resonators 101 and 103 and series resonator 102 are disposed separately on both the sides of the straight line 185 and then frequency adjustments of the parallel resonators 101 and 103 and a frequency adjustment of the series resonator 102 can individually be made to easily obtain excellent filter characteristics. <P>COPYRIGHT: (C)2009,JPO&INPIT |
