An acoustic wave device is disclosed. The acoustic wave device can include a multilayer piezoelectric substrate and an interdigital transducer electrode over the multilayer piezoelectric substrate. The interdigital transducer electrode includes a first layer and a second layer over the first layer. The interdigital transducer electrode has a non-zero tilt angle that provides an improved quality factor as compared to a zero tilt angle. The acoustic wave device is configured to generate a surface acoustic wave having a wavelength L. A total number of fingers of the interdigital transducer electrode is between 50 L and 100 L. A width between a finger of the interdigital transducer electrode and an adjacent finger of interdigital transducer electrode is between 20 L and 40 L.

A filter is provided that includes a set of cascaded resonator stages coupled between a filter input and a first filter output, wherein the filter includes a second filter output coupled to an output of a first or an intermediate one of the set of cascaded resonator stages. Another filter includes a set of cascaded resonator stages coupled between a first filter input and a filter output, wherein the filter includes a second filter input coupled to an input of an intermediate or a last one of the set of cascaded resonator stages. Both filters are configured to apply a first filter frequency response to a first signal propagating via the set of cascaded resonator stages, and apply a second filter frequency response to a second signal propagating via a subset of one or more of the set of cascaded resonator stages.

An acoustic wave device is disclosed. The acoustic wave device can include a multilayer piezoelectric substrate and an interdigital transducer electrode over the multilayer piezoelectric substrate. The interdigital transducer electrode includes a first layer and a second layer over the first layer. The interdigital transducer electrode has a tilt angle of at least 12 degrees. The acoustic wave device being configured to generate a surface acoustic wave having a wavelength L.

An acoustic wave device includes a piezoelectric substrate, first and second signal electrodes, and a first ground electrode on a first main surface of the piezoelectric substrate, at least one insulation layer on a second main surface of the piezoelectric substrate, first and second signal terminals provided indirectly on the second main surface with the insulation layer interposed therebetween, and a ground terminal on the second main surface. An acoustic wave filter is provided on the piezoelectric substrate. The first signal electrode and the first signal terminal are electrically coupled, the second signal electrode and the second signal terminal are electrically coupled, and the first ground electrode and the ground terminal are electrically coupled. The ground terminal includes a contact portion in contact with the second main surface of the piezoelectric substrate.

A filter is provided that includes a set of cascaded resonator stages coupled between a filter input and a first filter output, wherein the filter includes a second filter output coupled to an output of a first or an intermediate one of the set of cascaded resonator stages. Another filter includes a set of cascaded resonator stages coupled between a first filter input and a filter output, wherein the filter includes a second filter input coupled to an input of an intermediate or a last one of the set of cascaded resonator stages. Both filters are configured to apply a first filter frequency response to a first signal propagating via the set of cascaded resonator stages, and apply a second filter frequency response to a second signal propagating via a subset of one or more of the set of cascaded resonator stages.

A surface acoustic wave (SAW) device comprises a substrate and composite electrodes. The composite electrodes comprise a metal layer and a graphene layer. The SAW device may be used to satisfy requirements for the fifth generation (5G) mobile communication.

An elastic wave device includes first and second longitudinally coupled resonator elastic wave elements aligned on a piezoelectric substrate. A second reflector of the first longitudinally coupled resonator elastic wave element and a third reflector of the second longitudinally coupled resonator elastic wave element are adjacent to each other in an elastic wave propagation direction. A ground interconnection extends in a direction intersecting with the elastic wave propagation direction and in a region between the second reflector and the third reflector. A gap in one portion of the ground interconnection includes a different acoustic velocity portion where an acoustic velocity is different from an acoustic velocity in another portion of the ground interconnection.

A filter is provided that includes a set of cascaded resonator stages coupled between a filter input and a first filter output, wherein the filter includes a second filter output coupled to an output of a first or an intermediate one of the set of cascaded resonator stages. Another filter includes a set of cascaded resonator stages coupled between a first filter input and a filter output, wherein the filter includes a second filter input coupled to an input of an intermediate or a last one of the set of cascaded resonator stages. Both filters are configured to apply a first filter frequency response to a first signal propagating via the set of cascaded resonator stages, and apply a second filter frequency response to a second signal propagating via a subset of one or more of the set of cascaded resonator stages.

An elastic wave device includes first and second longitudinally coupled resonator elastic wave elements aligned on a piezoelectric substrate. A second reflector of the first longitudinally coupled resonator elastic wave element and a third reflector of the second longitudinally coupled resonator elastic wave element are adjacent to each other in an elastic wave propagation direction. A ground interconnection extends in a direction intersecting with the elastic wave propagation direction and in a region between the second reflector and the third reflector. A gap in one portion of the ground interconnection includes a different acoustic velocity portion where an acoustic velocity is different from an acoustic velocity in another portion of the ground interconnection.

An acoustic wave device includes a piezoelectric substrate, first and second signal electrodes, and a first ground electrode on a first main surface of the piezoelectric substrate, at least one insulation layer on a second main surface of the piezoelectric substrate, first and second signal terminals provided indirectly on the second main surface with the insulation layer interposed therebetween, and a ground terminal on the second main surface. An acoustic wave filter is provided on the piezoelectric substrate. The first signal electrode and the first signal terminal are electrically coupled, the second signal electrode and the second signal terminal are electrically coupled, and the first ground electrode and the ground terminal are electrically coupled. The ground terminal includes a contact portion in contact with the second main surface of the piezoelectric substrate.