Abstract: A surface acoustic wave device is disclosed. The surface acoustic wave device can include a single crystal support layer, an intermediate single crystal layer positioned over the single crystal support layer, a lithium based piezoelectric layer positioned over the intermediate single crystal layer, and an interdigital transducer electrode positioned over the lithium based piezoelectric layer, the surface acoustic wave device configured to generate a surface acoustic wave. The single crystal layer can be a quartz layer, such as a z-propagation quartz layer. A thermal conductivity of the single crystal support layer is greater than a thermal conductivity of the intermediate single crystal layer, and the thermal conductivity of the single crystal support layer is greater than a thermal conductivity of the lithium based piezoelectric 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: Disclosed herein is a bulk acoustic wave filter comprising a number of acoustic wave resonators, each acoustic wave resonator being encompassed by a polygon including vertices of a mesh optimized to provide a reduced filter size of the bulk acoustic wave filter integrated on a die.

Abstract: An acoustic wave device can have a plurality of coupling portions configured to electrically couple electrodes of the device to the substrate of the device to provide a bypass current pathway through the substrate for heat management. The substrate can be a semiconductor material, which can become more conductive as the temperature increases so that the bypass current pathway diverts more power through the substrate as the temperature increases. The acoustic wave device can be a surface acoustic wave device, which can have an interdigital transducer electrode that has the coupling portions on each of the bus bars and extending through the piezoelectric layer to contact the substrate. The acoustic wave device can be a bulk acoustic wave device in some implementations.

Abstract: Aspects of this disclosure relate to a bulk acoustic wave that includes a temperature compensation layer in thermal communication with a piezoelectric layer. The temperature compensation layer includes a silicon oxide composite that includes silicon oxide and a stiffening agent. The temperature compensation layer can have a positive temperature coefficient of variation. Related filters, multiplexers, radio frequency modules, radio frequency systems, 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 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: A bulk acoustic wave device configured to excite a second overtone mode as a main mode of operation. A piezoelectric layer is sandwiched between a bottom surface of a top electrode and a top surface of a bottom electrode. A temperature compensation layer is formed on the top surface of the top electrode.

Abstract: A surface acoustic wave device includes a piezoelectric substrate and a multi-layer interdigital transducer electrode disposed on the piezoelectric substrate. The multi-layer interdigital transducer electrode includes a first electrode layer and a second electrode layer. The second electrode layer is disposed between the piezoelectric substrate and the first electrode layer. The first electrode layer has a higher density than a density of the second electrode layer. The second electrode layer has a higher conductivity than a conductivity of the first electrode layer. Related radio frequency modules and wireless communication devices are also provided.

Abstract: An acoustic wave device can have a plurality of coupling portions configured to electrically couple electrodes of the device to the substrate of the device to provide a bypass current pathway through the substrate for heat management. The substrate can be a semiconductor material, which can become more conductive as the temperature increases so that the bypass current pathway diverts more power through the substrate as the temperature increases. The acoustic wave device can be a surface acoustic wave device, which can have an interdigital transducer electrode that has the coupling portions on each of the bus bars and extending through the piezoelectric layer to contact the substrate. The acoustic wave device can be a bulk acoustic wave device in some implementations.

Abstract: An acoustic wave device can have a plurality of coupling portions configured to electrically couple electrodes of the device to the substrate of the device to provide a bypass current pathway through the substrate for heat management. The substrate can be a semiconductor material, which can become more conductive as the temperature increases so that the bypass current pathway diverts more power through the substrate as the temperature increases. The acoustic wave device can be a surface acoustic wave device, which can have an interdigital transducer electrode that has the coupling portions on each of the bus bars and extending through the piezoelectric layer to contact the substrate. The acoustic wave device can be a bulk acoustic wave device in some implementations.

Abstract: An acoustic wave device structure has first and second electrode layers and a piezoelectric layer extending across series and shunt resonator sections. A piezoelectric layer is positioned between the first and second electrode layers. A first mass loading layer extends across the shunt resonator sections and is positioned between the first electrode layer and the piezoelectric layer. A second mass loading layer extends across the shunt resonator sections and at least one of the series resonator sections. The second electrode layer is positioned between the piezoelectric layer and the second mass loading layer.

Abstract: Aspects and embodiments disclosed herein include a bulk acoustic wave (BAW) device comprising a first electrode and a second electrode, at least one of the first electrode and the second electrode including at least one of a binary intermetallic compound, a metal nitride, a metal carbide, a metal carbonitride, a metal boride, a MXene, a MAX phase, or a MAB phase, and a piezoelectric material layer positioned between the first electrode and the second electrode.

Abstract: Aspects and embodiments disclosed herein include a bulk acoustic wave (BAW) device comprising a first electrode, a second electrode, a stack of at least two first piezoelectric material layers of the same polarity type sandwiched between the first electrode and the second electrode, and a first interposer sandwiched between the at least two first piezoelectric material layers and including at least one intermediate electrode, the BAW device being configured to excite an even overtone mode as the main mode of operation.

Abstract: An acoustic wave device includes a piezoelectric layer and an interdigital transducer electrode disposed over the piezoelectric layer. The interdigital transducer electrode is thicker in a center region of the interdigital transducer electrode than in a gap region of the interdigital transducer electrode to thereby reduce a mass loading of the interdigital transducer electrode in the gap region. The interdigital transducer electrode has a layer of more dense material disposed of a layer of less dense material.

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: 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: Aspects and embodiments disclosed herein include a bulk acoustic wave resonator including a material layer stack located in a central active region of the bulk acoustic wave resonator, the material layer stack comprising a bottom electrode, a first piezoelectric material layer disposed on an upper surface of the bottom electrode, a second piezoelectric material layer disposed on the first piezoelectric material layer, a polarity of the second piezoelectric material layer being opposite a polarity of the first piezoelectric material layer, an interposer layer disposed between the first piezoelectric material layer and the second piezoelectric material layer, and a top electrode having a lower surface disposed on an upper surface of the upper piezoelectric material layer.

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: Aspects and embodiments disclosed herein include a die comprising a plurality of bulk acoustic wave resonators. Each of the plurality of bulk acoustic wave resonators includes a piezoelectric material film having an active region. The plurality of bulk acoustic wave resonators include a first subset with metallic mass loading layers disposed above an upper electrode disposed on the piezoelectric material film in the active region and a second subset with metallic mass loading layers disposed below a lower electrode disposed on the piezoelectric film in the active region to cause the first subset to exhibit a different operating frequency than the second subset.