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.

Acoustic wave devices and interdigital transducer (IDT) arrangements for surface acoustic wave (SAW) devices are disclosed. Representative SAW devices are described herein that provide sharp transitions between passband frequencies and frequencies that are outside of desired passbands. A SAW device may include several IDTs arranged between reflective structures on a piezoelectric material and one or more additional IDTs or electrode pairs that are configured to modify the influence of parasitic capacitance, or other internal device capacitance, thereby improving steepness on the upper side of a passband as well as improving rejection for frequencies outside of the passband. The one or more additional IDTs or electrode pairs may be configured as at least one of a capacitor, an IDT capacitor, an IDT with a floating electrode, or combinations thereof.

A high-frequency circuit includes a signal wire connecting a pair of signal terminals; and a reference potential wire arranged along and close to the signal wire and connecting a pair of reference potential terminals.

A film bulk acoustic wave resonator (FBAR) is disclosed with raised and recessed frame portions formed in a top electrode. The FBAR can include a substrate, a piezoelectric film supported to oscillate in a direction opposite to a main surface of the substrate, and a pair of top and bottom electrodes formed respectively on top and bottom surfaces of the film. The recessed frame portion and the raised frame portion can be formed to extend adjacent to each other along a periphery of an active region of the film oscillating during an operation of the film on a top surface of the top electrode.

A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.

A stacked die XBAR filter device includes a first die containing one or more XBARs on a first surface, a second die containing one or more XBARs on a second surface, and one or more conductive vias through either the first die or the second die, where the first die is connected to the second die with the first surface facing the second surface.

An acoustic wave device defining a filter device having a pass band, includes a laminated substrate including first and second layers, a piezoelectric layer laminated on the first layer, and an excitation electrode on the piezoelectric layer. The first layer is a dielectric layer and is included in an intermediate layer laminated on the piezoelectric layer. A thickness of the first layer is defined as td, and combinations of a magnitude relationship of acoustic impedances of the piezoelectric layer and the first and second layers, and the thickness td are as shown in Table 1:

TABLE-US-00001 TABLE 1 Magnitude Relationship of Acoustic Impedance Zp > Zd Zp < Zd Zs > Zd td = n (1/2) λ td = (2n − 1) (1/4) λ Zs < Zd td = (2n − 1) (1/4) λ td = n (1/2) λ.

A bulk acoustic wave device includes a scandium-containing aluminum nitride film on a first electrode on a substrate, and a second electrode on the scandium-containing aluminum nitride film, the first electrode and the second electrode overlapping each other with the scandium-containing aluminum nitride film interposed therebetween. In the scandium-containing aluminum nitride film, along a thickness direction, in a first area on a first electrode side, a third area on a second electrode side, and a second area as a center area in the thickness direction between the first area and the third area, an orientation ratio in the first area is lower than an orientation ratio in the second area, or an orientation ratio in the third area is higher than the orientation ratio in the second area.

An acoustic wave device is provided that includes a support substrate, a piezoelectric layer on the support substrate, a first electrode and a second electrode on the piezoelectric layer in a lamination direction of the support substrate and the piezoelectric layer, the first and the second electrodes are opposed in a first direction that intersects with the lamination direction; and a space that defines either a cavity in a portion of the support substrate or an air gap between the support substrate and the piezoelectric layer. A portion of each of the first and the second electrodes overlaps the space in a plan view in the lamination direction. A first roughness of a major surface of the support substrate, opposite from the piezoelectric layer, is greater than a second roughness of a major surface of the piezoelectric layer on which the first and second electrodes are located.

A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.