CPC H03H 9/568 (2013.01) [H03H 3/02 (2013.01); H03H 9/02015 (2013.01); H03H 9/02031 (2013.01); H03H 9/02062 (2013.01); H03H 9/02228 (2013.01); H03H 9/132 (2013.01); H03H 9/174 (2013.01); H03H 9/176 (2013.01); H03H 9/562 (2013.01); H03H 9/564 (2013.01); H03H 2003/023 (2013.01); H03H 9/02039 (2013.01); H10N 30/877 (2023.02)] | 20 Claims |
1. A filter device comprising:
a substrate including a base and an intermediate dielectric layer;
a piezoelectric layer coupled to the substrate, the piezoelectric layer comprising a first diaphragm over a first cavity that at least partially extends in the intermediate dielectric layer of the substrate and a second diaphragm over a second cavity that at least partially extends in the intermediate dielectric layer of the substrate;
a first interdigital transducer (IDT) on a surface of the piezoelectric layer and having interleaved fingers on the first diaphragm;
a second interdigital transducer (IDT) on the surface of the piezoelectric layer and having interleaved fingers on the second diaphragm;
a first dielectric layer and between the interleaved fingers of the first IDT; and
a second dielectric layer between the interleaved fingers of the second IDT, wherein a thickness of the first dielectric layer is greater than a thickness of the second dielectric layer.
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