| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a ladder type filter in which a passband high frequency side attenuation amount can be enlarged, the ladder type filter including a plurality of elastic wave resonators, as serial arm resonators, with different logarithms of electrode fingers in IDT. <P>SOLUTION: A ladder type filter 1 includes a plurality of serial arm resonators composed of elastic wave resonators S1-S9 and a plurality of parallel arm resonators including elastic wave resonators P1-P6. A logarithm and an electrode finger pitch of an electrode finger in IDT of at least one elastic wave resonator S5 are different from a logarithm and an electrode finger pitch of an electrode finger in IDT of remaining at least one elastic wave resonator S6. <P>COPYRIGHT: (C)2013,JPO&INPIT |
