| 摘要 |
A filter element includes a plurality of multilayer filters 101. 102 that are connected in cascade, each of the plurality of multilayer filters including a plurality of piezoelectric thin-film resonators stacked vertically, each of the piezoelectric thin-film resonators including a piezoelectric film and a pair of first electrodes between which the piezoelectric film is interposed, and a capacitor 40 connected between an input terminal of one 101 of the plurality of multilayer filters of a preceding stage and an input terminal of another one 102 of the plurality of multilayer filters of a following stage, exciting directions of piezoelectric thin-film resonators 10a, 20b to which the input terminals of the multilayer filters of the preceding and following stages are connected being opposite to each other. |
