CPC H03H 9/02118 (2013.01) [H03F 3/189 (2013.01); H03H 9/0561 (2013.01); H03H 9/13 (2013.01); H03H 9/173 (2013.01); H03H 9/175 (2013.01); H03H 9/564 (2013.01); H03H 9/568 (2013.01); H03H 9/706 (2013.01); H03F 3/20 (2013.01); H03F 2200/294 (2013.01); H03F 2200/451 (2013.01); H04B 1/3827 (2013.01)] | 20 Claims |
1. A multiplexer comprising:
a first filter having a first passband, the first filter including a bulk acoustic wave resonator that includes first and second electrodes, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-layer raised frame structure including a first raised frame layer and a second raised frame layer, the first raised frame layer being positioned between a first electrode and the piezoelectric layer, the first raised frame layer having a lower acoustic impedance than the first electrode, and the second raised frame layer overlapping with the first raised frame layer; and
a second filter having a second passband, the second filter coupled to the first filter at a common node, and the first raised frame layer configured to move a raised frame mode of the bulk acoustic wave resonator away from the second passband.
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