| CPC H03H 9/568 (2013.01) [H03H 9/02157 (2013.01); H03H 9/0504 (2013.01); H03H 9/13 (2013.01); H03H 9/131 (2013.01); H03H 9/205 (2013.01)] | 24 Claims | 

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               1. A filter comprising: 
            one or more series bulk acoustic wave (BAW) resonators that include a first raised frame structure; and 
                one or more shunt bulk acoustic wave (BAW) resonators that have a second raised frame structure different from the first raised frame structure, the BAW resonators including a first electrode, a second electrode, and a piezoelectric layer between the first electrode and the second electrode, the first raised frame structure or the second raised frame structure including a first raised frame layer and a second raised frame layer having a higher acoustic impedance than the first raised frame layer, the second raised frame layer overlapping a portion of the first raised frame layer, and the first raised frame layer extending further inward than the second raised frame layer by a distance that is between about 50% and about 100% of a combined thickness of the first electrode, the piezoelectric layer, and the second electrode. 
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