Abstract: A surface acoustic wave (SAW) resonator comprises a plurality of interdigital transducer (IDT) electrodes disposed on a multilayer piezoelectric substrate including a layer of piezoelectric material having a lower surface bonded to an upper surface of a layer of a dielectric material. The dielectric material has a lower surface bonded to an upper surface of a carrier substrate. The plurality of IDT electrodes include an upper layer and a lower layer. The upper layer is formed of a material having a higher conductivity than the lower layer. The lower layer is formed of a material having a higher density than the upper layer to provide for reduction in size of the SAW resonator.

Abstract: A method of manufacturing a packaged surface acoustic wave filter chip is disclosed. The method can include providing a structure having first interdigital transducer electrodes formed with a first piezoelectric layer, second interdigital transducer electrodes formed with a second piezoelectric layer, and a substrate between the first and second piezoelectric layers. The method can include forming a plurality of through electrodes extending at least partially through a thickness of the structure such that a first set of through electrodes of the plurality of through electrodes are electrically connected to the first interdigital transducer electrodes and a second set of through electrodes of the plurality of through electrodes are electrically isolated from the first interdigital transducer electrodes.

Abstract: A packaged acoustic wave component includes a support substrate, a multi-layer piezoelectric substrate disposed over a first side of the support substrate, one or more metal layers disposed on a second side of the support substrate that is opposite the first side of the support substrate, and one or more surface acoustic wave resonators or filters disposed over the multi-layer piezoelectric substrate. The one or more surface acoustic wave resonators or filters include a multi-mode surface acoustic wave resonator or filter (e.g., dual mode surface acoustic wave resonator or filter). One or more vias extend through the support substrate and electrically connect the multi-mode surface acoustic wave resonator or filter and the one or more metal layers to provide a ground connection for the multi-mode surface acoustic wave resonator or filter, while reducing parasitic inductance.

Abstract: A method of manufacturing a packaged acoustic wave component includes forming a support substrate, forming a multi-layer piezoelectric substrate over a first side of the support substrate, and forming one or more metal layers over a second side of the support substrate that is opposite the first side of the support substrate. The method also includes forming one or more surface acoustic wave resonators or filters (including a multi-mode surface acoustic wave resonator or filter) over the multi-layer piezoelectric substrate. The method also includes forming one or more vias through the support substrate, and electrically connecting the multi-mode surface acoustic wave resonator or filter and the metal layers with the vias to provide a ground connection for the multi-mode surface acoustic wave resonator or filter.

Abstract: Aspects of this disclosure relate to an acoustic wave device that includes high velocity layers on opposing sides of a piezoelectric layer. A low velocity layer can be positioned between the piezoelectric layer and one of the high velocity layers, in which the low velocity layer has a lower acoustic velocity than the high velocity layers. The acoustic wave device can be configured to generate a boundary acoustic wave such that acoustic energy is concentrated at a boundary of the piezoelectric layer and the low velocity layer.

Abstract: An acoustic wave device is disclosed. The acoustic wave device can include a piezoelectric layer positioned over a substrate. The acoustic wave device can also include an interdigital transducer electrode positioned over the piezoelectric layer. The acoustic wave device can also include a grounding structure positioned over the piezoelectric layer. The acoustic wave device can also include a conductive layer positioned between the piezoelectric layer and the substrate. The acoustic wave device can further include an electrical pathway that electrically connects the conductive layer to the grounding structure.

Abstract: A surface acoustic wave filter is disclosed. The surface acoustic wave filter includes a substrate, and first and second surface acoustic wave filter structures disposed on first and second main surfaces of the substrate, respectively. The first surface acoustic wave filter structure includes a first piezoelectric layer a plurality of first surface acoustic wave resonators formed on a top surface of the first piezoelectric layer, and a first wiring layer connecting the first surface acoustic wave resonators to each other. The second surface acoustic wave filter structure includes a second piezoelectric layer, a plurality of second surface acoustic wave resonators formed on a bottom surface of the second piezoelectric layer, and a second wiring layer connecting the second surface acoustic wave resonators to each other. A plurality of through electrodes extends through the substrate, the first piezoelectric layer, and the second piezoelectric layer.

Abstract: An acoustic wave device is disclosed. The acoustic wave device can include a piezoelectric layer positioned over a substrate. The acoustic wave device can also include an interdigital transducer electrode positioned over the piezoelectric layer. The acoustic wave device can also include a grounding structure positioned over the piezoelectric layer. The acoustic wave device can also include a conductive layer positioned under the substrate such that the substrate is positioned between the conductive layer and the grounding structure. The acoustic wave device can further include an electrical pathway that electrically connects the conductive layer to the grounding structure.

Abstract: Surface acoustic wave resonators are disclosed. In certain embodiments, a surface acoustic wave resonator can include a high impedance layer, a piezoelectric layer over the high impedance layer, an interdigital transducer electrode over the piezoelectric layer, and a low impedance layer between the high impedance layer and the piezoelectric layer. An acoustic impedance of the high impedance layer is greater than an acoustic impedance of the piezoelectric layer. An acoustic impedance of the low impedance layer is lower than the acoustic impedance of the high impedance layer. The piezoelectric layer can have a cut angle in a range from 115° to 135°. The surface acoustic wave resonator is configured to generate a Rayleigh mode surface acoustic wave having a wavelength of ?.

Abstract: A method of making a surface acoustic wave package includes bonding a piezoelectric layer over a substrate and attaching a metal structure over the substrate, with the piezoelectric layer positioned between at least a portion of the substrate and at least a portion of the metal structure. The method also includes removing (e.g., etching) an outer boundary of the piezoelectric layer so that a resulting outer edge of the piezoelectric layer is spaced inward of an inner edge of the metal package (e.g., the piezoelectric layer does not contact the metal package). The method inhibit damage to the piezoelectric layer due to a stress differential between the substrate and the thermally conductive structure during a packaging process.

Abstract: A surface acoustic wave package has a piezoelectric layer over a substrate and a thermally conductive structure attached to the substrate. The outer boundary of the piezoelectric layer is removed (e.g., etched) so that a resulting outer edge of the piezoelectric layer is spaced inward of an inner edge of the thermally conductive structure. The piezoelectric layer does not contact the thermally conductive structure to inhibit damage to the piezoelectric layer due to a stress differential between the substrate and the thermally conductive structure during a packaging process.

Abstract: A surface acoustic wave device can have a piezoelectric layer and at least one interdigital transducer electrode thereon with a trapezoidal shape. This can be useful to fill dead space or voids between nonparallel elements on the layer. For example, an array with ranks of slanted interdigital transducer electrodes may not be aligned with non-slanted elements (e.g., a surface acoustic wave filter). This can leave voids or openings with unused portions of the piezoelectric layer. Trapezoidal elements such as those described here can solve this problem and help suppress transverse modes.

Abstract: A piezoelectric microelectromechanical system microphone comprises a support substrate, a membrane including a piezoelectric material attached to the support substrate and configured to deform and generate an electrical potential responsive to impingement of sound waves on the membrane, and a compliant anchor including a trench defined in the support substrate about a portion of a perimeter of the membrane to increase sensitivity of the piezoelectric microelectromechanical system microphone.

Abstract: A method of manufacturing an acoustic wave device is disclosed. The method includes attaching a support layer to a ceramic layer. The support layer has a higher thermal conductivity than the ceramic layer. The ceramic layer can be a polycrystalline spinel layer. The method also includes bonding a piezoelectric layer to a surface of the ceramic layer. The method further includes forming an interdigital transducer electrode over the piezoelectric layer.

Abstract: Aspects of this disclosure relate to acoustic wave devices on stacked die. A first die can include first acoustic wave device configured to generate a boundary acoustic wave. A second die can include a second acoustic wave device configured to generate a second boundary acoustic wave, in which the second die is stacked with the first die. The first acoustic wave resonator can include a piezoelectric layer, an interdigital transducer electrode on the piezoelectric layer, and high acoustic velocity layers on opposing sides of the piezoelectric layer. The high acoustic velocity layers can each have an acoustic velocity that is greater than a velocity of the boundary acoustic wave.

Abstract: A packaged surface acoustic wave device is disclosed. the packaged surface acoustic wave device can include a support substrate that includes a conductive via formed therein, a piezoelectric layer over the support substrate, an interdigital transducer electrode over the piezoelectric layer, a roof structure over the interdigital transducer electrode, and a conductive pillar directly over the conductive via. The conductive pillar supports the roof structure and defines at least a portion of a signal pathway between the interdigital transducer electrode and the conductive via.

Abstract: A packaged surface acoustic wave device is disclosed. the packaged surface acoustic wave device can include a support substrate that includes a conductive via formed therein, a piezoelectric layer over the support substrate, an interdigital transducer electrode over the piezoelectric layer, a roof structure over the interdigital transducer electrode, and a conductive pillar between the support substrate and the roof structure. The conductive pillar supports the roof structure and defines at least a portion of an electrical pathway between the interdigital transducer electrode and the conductive via. The roof structure is configured such that there is no signal communication between the conductive pillar and the roof structure.

Abstract: A packaged surface acoustic wave device is disclosed. The packaged surface acoustic wave device can include a support substrate that has a first side and a second side opposite the first side. The support substrate including a conductive via extending vertically between the first side to the second side. The packaged surface acoustic wave device can include a piezoelectric layer over the first side of the support substrate, an interdigital transducer electrode over the piezoelectric layer, a roof structure over the interdigital transducer electrode, and a conductive pillar between the first side of the support substrate and the roof structure. The conductive pillar supports the roof structure and defines at least a portion of an electrical pathway between the interdigital transducer electrode and the conductive via. A maximum horizontal dimension of the conductive pillar is greater than a maximum horizontal dimension of the conductive via.

Abstract: An acoustic wave resonator comprises a carrier substrate, a layer of dielectric material disposed on an upper surface of the carrier substrate, and a layer of piezoelectric material disposed above the layer of dielectric material. The layer of piezoelectric material includes a pair of opposing terminating edges that are coterminous with the layer of dielectric material. One or more interdigital transducers (IDTs) are disposed on the layer of piezoelectric material. The opposing terminating edges sandwich the one or more interdigital transducers, and in some examples, a pair of reflector gratings disposed on the layer of piezoelectric material and each including less than eight reflector fingers. The opposing terminating edges provide edge reflections that allow a reduction in size or a complete removal of the reflector gratings, resulting in a smaller acoustic wave resonator compared to conventional devices while maintaining a comparable performance.

Abstract: An acoustic wave device, a method of manufacture of the same, and a radio frequency filter including the same. The acoustic wave device comprises a multilayer piezoelectric substrate (MPS) including a layer of piezoelectric material having a lower surface disposed on an upper surface of a layer of a dielectric material having a lower surface disposed on an upper surface of a carrier substrate. An interdigital transducer (IDT) is disposed on the multilayer piezoelectric substrate and includes an active region configured to generate an acoustic wave. First and second high impedance portions are included within the multilayer piezoelectric substrate, the first and second high impedance portions each positioned outside the active region of the interdigital transducer and extending in the direction of propagation of the acoustic wave to be generated by the interdigital transducer. The first and second high impedance portions reduce side leakage and suppress transverse modes.