A bulk acoustic wave (BAW) resonator includes a piezoelectric layer, a first electrode layer disposed on a first side of the piezoelectric layer and including a first electrode and an additional electrode electrically isolated from each other, a second electrode layer disposed on a second side of the piezoelectric layer and including a second electrode, one or more conductive pads disposed on the second side of the piezoelectric layer and at least including an interconnection pad electrically connected to the second electrode and the additional electrode, a carrier structure disposed on the first side of the piezoelectric layer, a cover structure disposed on the second side of the piezoelectric layer and including a cover bonding layer and a cover substrate. A first cavity is disposed between the carrier structure and the piezoelectric layer. A second cavity is disposed between the cover structure and the piezoelectric layer.

Techniques for improving acoustic wave device structures are disclosed, including filters and systems that may include such devices. An acoustic wave device may include a substrate. The acoustic wave device may include first and second layers of piezoelectric material acoustically coupled with one another, in which the first layer of piezoelectric material has a first piezoelectric axis orientation, and the second layer of piezoelectric material has a second piezoelectric axis orientation that substantially opposes the first piezoelectric axis orientation of the first layer of piezoelectric material. The acoustic wave device may include an interposer layer interposed between the first and second layers of piezoelectric material. The interposer may facilitate an enhancement of an electromechanical coupling coefficient of the acoustic wave device.

An RF diplexer circuit device using modified lattice, lattice, and ladder circuit topologies. The diplexer can include a pair of filter circuits, each with a plurality of series resonator devices and shunt resonator devices. In the ladder topology, the series resonator devices are connected in series while shunt resonator devices are coupled in parallel to the nodes between the resonator devices. In the lattice topology, a top and a bottom serial configurations each includes a plurality of series resonator devices, and a pair of shunt resonators is cross-coupled between each pair of a top serial configuration resonator and a bottom serial configuration resonator. The modified lattice topology adds baluns or inductor devices between top and bottom nodes of the top and bottom serial configurations of the lattice configuration. A multiplexing device or inductor device can be configured to select between the signals coming through the first and second filter circuits.

Techniques for improving acoustic wave device structures are disclosed, including at least filters and systems that may include such devices. An acoustic wave device may include at least a substrate. The acoustic wave device may include at least a first piezoelectric layer and a second piezoelectric layer and a third piezoelectric layer. The second piezoelectric layer may have a second piezoelectric axis orientation. The third piezoelectric layer may have a third piezoelectric axis orientation that substantially opposes the second piezoelectric axis orientation of the second piezoelectric layer. The acoustic wave device may include an interposer layer coupled between the second piezoelectric layer and the third piezoelectric layer.

A resonator, a resonator assembly, a filter, an electronic device, and a method for manufacturing the resonator. The resonator comprises: a substrate, comprising a first surface and a second surface opposite to each other; a first electrode, located on the first surface, where the first electrode comprises a first protruding portion protruding away from the first surface and a first flat portion attached on the first surface, and a cavity is formed between the first protruding portion and the first surface; a piezoelectric layer, located at a side of the first electrode away from the substrate, where the piezoelectric layer extends in parallel with the first surface; and a second electrode, located at a side of the piezoelectric layer away from the first electrode.

A resonator, a resonator assembly, a filter, an electronic device, a method for fabricating the resonator, and a packaging structure are provided. The bulk acoustic resonator includes a substrate, a first electrode, a second electrode, an acoustic reflection structure between the first electrode and the substrate, and a piezoelectric layer arranged between the second electrode and the first electrode. In a direction perpendicular to the substrate, an overlapping region of the acoustic reflection structure, the first electrode, the piezoelectric layer and the second electrode is an active region that is annular. A distance from a point A on an inner edge of the active region to a center of the resonator is D, and a shortest distance from A to an outer edge of the active region is W, where 0.1W/D10. The heat dissipation rate of the resonator can be improved by modifying W.

An acoustic wave device includes a piezoelectric layer provided with a part of the piezoelectric layer between lower and upper electrodes and having a through hole along a resonance region, an insertion film provided between the lower electrode and the piezoelectric layer and having a resistivity higher than those of the lower electrode and the upper electrode, a first film provided on a side of the upper electrode, a second film provided between the side surface of the upper electrode and the first film, and a third film provided between the side surface of the upper electrode and the second film or between the first film and the second film, a concentration of a first element of the third film being higher than that of the second film and a concentration of a second element of the third film being lower than that of the second film.

A film bulk acoustic resonator (FBAR) chip and package structure with improved power tolerance includes: a first substrate having a plurality of FBARs each having a bottom electrode, a piezoelectric material, and a top electrode, and first bonding pads connected to the bottom electrodes or the top electrodes of the FBARs; and a second substrate having a plurality of vias passing therethrough, second bonding pads located on one end surface of the vias facing the first substrate, and external connection pads located on the other end surface of the vias which does not face the first substrate, wherein the first substrate and the second substrate are bonded by means of bonding of the first bonding pads and the second bonding pads.

An acoustic wave device includes a support, a piezoelectric layer including first and second main surfaces, and an IDT electrode including first and second busbar portions, and first and second electrode fingers connected to the first and second busbar portions and being interdigitated with each other. A region in which first and second electrode fingers adjacent to each other overlap each other is an intersection region. A cavity portion is provided in the support and overlaps the intersection region. At least one of the first and second busbar portions includes an outer busbar not overlapping the cavity portion, and at least one of protruding electrodes extending from the outer busbar toward the intersection region. The at least one protruding electrode overlaps an outer peripheral edge of the cavity portion.

A bulk acoustic wave resonator and a preparation method thereof, the bulk acoustic wave resonator includes a first electrode and a second electrode, and a piezoelectric film between the first and second electrodes, the piezoelectric film includes n layers of polarized piezoelectric films, and the polarities of any two adjacent layers of the polarized piezoelectric films are opposite. The acoustic mirror is disposed between the substrate and the first electrode, by preparing the polarized piezoelectric films with opposite polarities in layers, polarity inversion is achieved. The bulk acoustic wave resonator of the present disclosure can reduce the requirements for the piezoelectric film materials and increase the resonant frequency under the condition of not reducing the total thickness of the piezoelectric film or introducing a transition electrode. The process is simplified, the acoustic wave loss is reduced, and the quality factor is improved.