CPC H03H 9/02157 (2013.01) [H03H 9/02015 (2013.01); H03H 9/0211 (2013.01); H03H 9/13 (2013.01); H03H 9/205 (2013.01)] | 19 Claims |
1. An acoustic wave device configured to use a thickness shear primary mode bulk wave, the acoustic wave device comprising:
a piezoelectric layer; and
a first electrode and a second electrode facing each other in a direction intersecting with a thickness direction of the piezoelectric layer; wherein
a material of the piezoelectric layer is lithium niobate or lithium tantalate;
multiple electrode portions including the first electrode and the second electrode are provided;
a first divided resonator and a second divided resonator connected in series without another resonator being connected between the first divided resonator and the second divided resonator, or connected in parallel with each other to a same connection node on a path connecting an input terminal and an output terminal;
a support substrate including a first main surface and a second main surface opposed to each other are provided;
the first divided resonator includes a first electrode portion of the multiple electrode portions and a first installation portion of the piezoelectric layer including a first region in which the first electrode portion is provided;
the second divided resonator includes a second electrode portion of the multiple electrode portions and a second installation portion of the piezoelectric layer including a second region in which the second electrode portion is provided;
the piezoelectric layer is directly or indirectly provided on the support substrate;
the support substrate includes:
a first energy confinement layer at least partially overlapping with the first region of the piezoelectric layer in a plan view from the thickness direction of the piezoelectric layer; and
a second energy confinement layer at least partially overlapping with the second region of the piezoelectric layer in a plan view from the thickness direction of the piezoelectric layer; and
the first energy confinement layer and the second energy confinement layer are integrally provided with each other in the support substrate.
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