| 摘要 |
PROBLEM TO BE SOLVED: To provide a stacked BAW filter which has high mechanical reliability and a wide bandwidth and can deal with high frequency. SOLUTION: An output electrode 2, an output piezoelectric substance 3, a ground electrode 4, an input piezoelectric substance 5 and an input electrode 6 are successively stacked on a substrate 1 having a vibration space A so as to cover this space. In such a constitution of a stacked filter, the substance 3 and 5 are constituted of ferroelectric substances and the substance 3 and/or 5 comprise a layered product including the piezoelectric substances 3a and 3b having different polarizing directions.
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