An acoustic resonator comprises a first electrode and second electrode comprising a plurality of sides. At least one of the sides of the second electrode comprises a cantilevered portion. A piezoelectric layer is disposed between the first and second electrodes. A bridge disposed adjacent to one of the sides of the second 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.

A volume acoustic device. The volume acoustic device includes a first electrode and a second electrode and a piezoelectric element disposed between the first electrode and the second electrode. The piezoelectric element is configured such that a first electromagnetic signal fed into the first electrode is converted to an acoustic signal in the piezoelectric element, and the acoustic signal is converted back into a second electromagnetic signal in the second electrode. A dielectric layer surrounds the first electrode, the second electrode, and the piezoelectric element, and has a substantially planar surface. At least one separation trench at least partially surrounds the piezoelectric element is formed in the dielectric layer.

An acoustic resonator forms a component of an FBAR filter that includes a trap-rich layer to avoid parasitic conduction by degrading carrier lifetimes of a free charge carriers. The acoustic resonator has a first electrode, a second electrode disposed parallel to the first planar portion and a piezoelectric layer disposed between and contacting both the first and second planar electrodes. A silicon-based a support layer is bonded to the second electrode and includes a trap region. The acoustic resonator may be manufactured by (a) depositing the trap region on the support layer; (b) oxidizing a surface of the trap region; (c) depositing a bonding layer on the oxidized surface of the trap region; (d) bonding a first electrode to the bonding layer; (e) contacting a first side of a piezoelectric layer to the electrode; and (f) contacting a second side of the piezoelectric layer a second electrode.

A transducer structure for a surface acoustic device comprises a composite substrate comprising a piezoelectric layer, a pair of inter-digitated comb electrodes, comprising a plurality of electrode means with a pitch p satisfying the Bragg condition, wherein the inter-digitated comb electrodes are embedded in the piezoelectric layer such that, in use, the excitation of a wave propagating mode in the volume of the electrode means is taking place and is the predominant propagating mode of the structure. The present disclosure relates also to an acoustic wave device comprising at least one transducer structure as described above and to a method for fabricating the transducer structure. The present disclosure relates also to the use of the frequency of the bulk wave propagating in the electrode means of the transducer structure in an acoustic wave device to generate contribution at high frequency, in particular, above 3 GHz.