| 摘要 |
An acoustic wave filter including a substrate (112), a signal line (108) disposed on the substrate and connecting a first signal terminal (102) to a second signal terminal (104), a plurality of series resonators (S11, S12, S13, S14, S15) connected to the signal line (108) in series, and a plurality of parallel resonators (P11, P12, P13, P14, P15) connected to the signal line. At least one of the series resonator having an anti-resonant frequency closest to the passband of the filter among the plurality of series resonators, and/or at least one the parallel resonator (P13, P14) having a resonant frequency closest to the passband of the filter among the plurality of parallel resonators, is covered with a dielectric film (114) that has a thickness (T1) that is relatively thicker than a dielectric film having a thickness (T2) covering the other series and/or parallel resonators (P11, P15). |
