Abstract: An acoustic wave device configured to generate a surface acoustic wave having a wavelength L is disclosed. The acoustic wave device can include a substrate, a piezoelectric layer that includes lithium niobate, an interdigital transducer electrode, an overcoat dielectric layer, and/or a raised frame structure. The piezoelectric layer is disposed at least partially between the substrate and the interdigital transducer electrode. The overcoat dielectric layer is positioned over the interdigital transducer electrode. The raised frame structure is positioned over the overcoat dielectric layer. The raised frame structure includes a material of the overcoat dielectric layer. The raised frame structure is positioned in an edge region within 0.25 L and 0.45 L from an edge of an active region where the surface acoustic wave is generated. The acoustic wave device can include a trap-rich layer over the substrate and an intervening dielectric layer over the trap-rich layer.

Abstract: An acoustic wave device configured to generate a surface acoustic wave having a wavelength L is disclosed. The acoustic wave device can include a substrate, a piezoelectric layer that includes lithium niobate, an interdigital transducer electrode, an overcoat dielectric layer, and/or a raised frame structure. The piezoelectric layer can have a trench in an edge region within 0.25L and 0.45L from an edge of an active region where the surface acoustic wave is generated. The piezoelectric layer is disposed at least partially between the substrate and the interdigital transducer electrode. The overcoat dielectric layer is positioned over the interdigital transducer electrode. The raised frame structure is positioned over the overcoat dielectric layer. The raised frame structure is positioned in an edge region of the active region. The acoustic wave device can include a trap-rich layer over the substrate and an intervening dielectric layer over the trap-rich layer.

Abstract: Aspects of this disclosure relate to a surface acoustic wave filter with an acoustic velocity adjustment structure. The surface acoustic wave filter can include a first interdigital transducer electrode disposed on a piezoelectric layer, an acoustic reflector disposed on the piezoelectric layer, and a second interdigital transducer electrode disposed on the piezoelectric layer. The second interdigital transducer electrode is longitudinally coupled to the first interdigital transducer electrode and positioned between the first interdigital transducer electrode and the acoustic reflector. The acoustic velocity adjustment structure can be positioned over at least a gap between the first interdigital transducer electrode and the second interdigital transducer electrode.

Abstract: Aspects of this disclosure relate to a surface acoustic wave device that includes a first reflector over a piezoelectric layer, a second reflector over the piezoelectric layer, and an interdigital transducer electrode structure over the piezoelectric layer and positioned between the first reflector and the second reflector. The surface acoustic wave device includes a velocity adjustment layer arranged to adjust acoustic velocity in a region of the surface acoustic wave device. The velocity adjustment layer can be a high speed layer or a low speed layer.

Abstract: Aspects of this disclosure relate to a surface acoustic wave device with a vertical stack over a piezoelectric layer. The vertical stack can include a first acoustic reflector disposed on the piezoelectric layer, a second acoustic reflector disposed on the piezoelectric layer, and an interdigital transducer electrode disposed on the piezoelectric layer and positioned between the first acoustic reflector and the second acoustic reflector. The interdigital transducer electrode has a first side that is closer to the first acoustic reflector and a second side that is closer to the second acoustic reflector. A vertical arrangement of the vertical stack can be configured such that an acoustic wave propagation velocity of a first region between the first side and a first reflector is faster than an acoustic wave propagation velocity of a second region between the first side and the second side.

Abstract: Aspects of this disclosure relate to an acoustic wave device with a piezoelectric layer that includes a wurtzite structure. The wurtzite structure can include aluminum nitride and silicon carbide. Related piezoelectric layers, acoustic wave filters, radio frequency modules, wireless communication devices, and methods are disclosed.

Abstract: Aspects of this disclosure relate to an acoustic wave device with a temperature compensation layer that includes silicon oxycarbide. The temperature compensation layer can be in physical contact with at least a portion of a piezoelectric layer of the acoustic wave device. The acoustic wave device can be a surface acoustic wave device in certain applications. The acoustic wave device can be a bulk acoustic wave device in some other applications. Related acoustic wave filters, radio frequency modules, wireless communication devices, and methods are disclosed.

Abstract: Aspects of this disclosure relate to an acoustic wave device with a silicon oxycarbide layer over a trap rich layer. The acoustic wave device can include a piezoelectric layer over the silicon oxycarbide. The acoustic wave device can be a surface acoustic wave device in certain applications. The acoustic wave device can be a bulk acoustic wave device in some other applications. Related acoustic wave filters, radio frequency modules, wireless communication devices, and methods are disclosed.

Abstract: Aspects of this disclosure relate to an acoustic wave device with a piezoelectric layer that includes a wurtzite structure. The wurtzite structure can include a group 2 element and have a high acoustic velocity. For example, the wurtzite structure can include a carbide and the group 2 element can be carbon of the carbide. The high acoustic velocity can be over 10,000 meters per second. Related piezoelectric layers, acoustic wave filters, radio frequency modules, wireless communication devices, and methods are disclosed.

Abstract: A method of manufacturing an acoustic wave device is provided. The method of manufacturing the acoustic wave device comprises providing a layer of piezoelectric material, disposing a pair of interdigital transducer electrodes on an upper surface of the layer of piezoelectric material, each interdigital transducer electrode including a bus bar and a plurality of electrode fingers extending from the bus bar towards an edge region of the interdigital transducer electrode at the distal ends of the electrode fingers, and etching trench portions into the upper surface of the layer of piezoelectric material, the trench portions overlapping with the edge regions of the interdigital transducer electrodes. The formation of the trench portions through etching results in an easier fabrication, that is less likely to damage the interdigital transducer electrodes.

Abstract: An acoustic wave device, a radio frequency filter and an electronics module are provided. The acoustic wave device comprises a layer of piezoelectric material, a pair of interdigital transducer electrodes disposed on an upper surface of the layer of piezoelectric material, each interdigital transducer electrode including a bus bar and a plurality of electrode fingers extending from the bus bar towards an edge region of the interdigital transducer electrode at the distal ends of the electrode fingers, and trench portions located in the upper surface of the layer of piezoelectric material, the trench portions overlapping with the edge regions of the interdigital transducer electrodes. The acoustic wave device provides effective suppression of transverse modes.

Abstract: An acoustic wave device, a radio frequency filter and an electronics module are provided. The acoustic wave device, comprises a layer of piezoelectric material, a pair of interdigital transducer electrodes disposed on an upper surface of the layer of piezoelectric material, each interdigital transducer electrode including a bus bar and a plurality of electrode fingers extending from the bus bar through a central region of the interdigital transducer electrode towards an edge region of the interdigital transducer electrode, each of the plurality of electrode fingers having a width in a direction perpendicular to the extension of the electrode fingers that is smaller in the edge regions than in the central regions, and trench portions located in the upper surface of the layer of piezoelectric material, the trench portions overlapping with the edge regions of the interdigital transducer electrodes. The acoustic wave device provides effective suppression of transverse modes.

Abstract: A first acoustic wave device can have a piezoelectric layer between a first electrode and a second electrode. The first acoustic wave device can have a first shape and a first area. A second acoustic wave device can be coupled to the first acoustic wave device to at least partially cancel a second harmonic response of the first acoustic wave device. The second acoustic wave device can have a piezoelectric layer between a first electrode and a second electrode. The second acoustic wave device can have a second shape that is different from the first shape and a second area that is within a threshold amount of the first area.

Abstract: A first acoustic wave device can have a piezoelectric layer between a first electrode and a second electrode. The first acoustic wave device can have a first shape and a first area. A second acoustic wave device can be coupled to the first acoustic wave device to at least partially cancel a second harmonic response of the first acoustic wave device. The second acoustic wave device can have a piezoelectric layer between a first electrode and a second electrode. The second acoustic wave device can have a second shape that is different from the first shape and a second area that is within a threshold amount of the first area.

Abstract: Embodiments of this disclosure relate to multiplexers that include acoustic wave filters for filtering radio frequency signals. In certain embodiments, a multiplexer includes a first acoustic wave filter including bulk acoustic wave resonators and a second acoustic wave filter including multilayer piezoelectric substrate surface acoustic wave resonators. The second acoustic wave filter can have a second pass band that is above a first pass band of the first acoustic wave filter. Related acoustic filter assemblies, packaged radio frequency modules, wireless communication devices, and methods are disclosed.

Abstract: A bulk acoustic resonator comprises a membrane including a piezoelectric film having multiple layers of piezoelectric material. At least one of the multiple layers of piezoelectric material has a different dopant concentration than another of the multiple layers of piezoelectric material.

Abstract: The present disclosure provides a bulk acoustic wave resonator comprising a piezoelectric layer and a top electrode disposed on a first surface of the piezoelectric layer. The bulk acoustic wave resonator has a central region, a first outer region, and a first raised frame region between the central region and the first outer region. The top electrode has a first thickness within the central region, a second thickness within the first raised frame region, and a third thickness within the first outer region, the second thickness being greater than both the first thickness and the third thickness. A die, filter, radio-frequency module and wireless mobile device are also provided.

Abstract: A bulk acoustic wave resonator having a central region, an outer region, and a raised frame region between the central region and the outer region is disclosed. The bulk acoustic wave resonator can include a piezoelectric layer and a top electrode over the piezoelectric layer. The top electrode is disposed at least in the central region, the outer region, and the raised frame region, the top electrode including a first layer and a second layer. A material of the first layer is different from the material of the second layer.

Abstract: A bulk acoustic wave resonator having a central region, an outer region, and a raised frame region between the central region and the outer region is disclosed. The bulk acoustic wave resonator can include a piezoelectric layer and a top electrode over the piezoelectric layer. The top electrode is disposed at least in the central region, the outer region, and the raised frame region. The top electrode is configured such that a resonant frequency in the outer region is higher than a resonant frequency in the central region.

Abstract: A film bulk acoustic wave resonator (FBAR) comprises a recessed frame region including an undulating perimeter.