A film bulk acoustic wave resonator (FBAR) comprises a recessed frame region including an undulating perimeter.

A bulk-acoustic wave resonator includes: a substrate; a lower electrode disposed on the substrate; a piezoelectric layer at least partially covering the lower electrode; and an upper electrode at least partially covering the piezoelectric layer. On a surface of the bulk-acoustic wave resonator, a centroid of an active area in which the lower electrode, the piezoelectric layer, and the upper electrode all overlap each other is aligned with a center of a rectangle defining an aspect ratio of the active area. The active area has a shape of a polygon symmetrical with respect to at least one axis passing through the center of the rectangle defining the aspect ratio. The aspect ratio is greater than or equal to 2 and less than or equal to 10.

An acoustic resonator device includes a portion of a piezoelectric plate is a diaphragm spanning a cavity in a substrate. A conductor pattern on a surface of the piezoelectric plate includes an interdigital transducer (IDT) with a first busbar, a second busbar, and a. plurality of interleaved fingers extending alternately from the first and second busbars, first and second reflector elementsproximate and parallel to a first finger of the interleaved fingers, and third and fourth reflector element proximate and parallel to a last finger of the interleaved fingers. Overlapping portions of the interleaved fingers and the first to fourth reflector elements are on the diaphragm. pr1 is a center-to-center distance of the first and second reflector elements and a center-to-center distance of the third and fourth reflector elements, p is a pitch of the interleaved fingers, and 1.1p≤pr1≤1.5p.

An acoustic wave device includes a piezoelectric substrate a reverse-velocity surface of which is convex, an interdigital transducer electrode disposed on the piezoelectric substrate, and mass addition films stacked above the interdigital transducer electrode. The interdigital transducer electrode includes a central region, first and second edge regions, first and second gap regions located outside the first and second edge regions, first and second inner busbar regions, and first and second outer busbar regions. The mass addition films are stacked in at least the first and second edge regions and the first and second inner busbar regions.

A ladder filter comprises a plurality of series arm bulk acoustic wave resonators electrically connected in series between an input port and an output port of the ladder filter and a plurality of shunt bulk acoustic wave resonators electrically connected in parallel between adjacent ones of the plurality of series arm bulk acoustic wave resonators and ground, at least one of the plurality of shunt bulk acoustic wave resonators including raised frame regions having a first width, at least one of the plurality of series arm bulk acoustic wave resonators having one of raised frame regions having a second width less than the first width or lacking raised frame regions.

A laterally excited bulk acoustic wave device is disclosed. The laterally excited bulk acoustic wave device can include a support substrate, a solid acoustic mirror on the support substrate, a piezoelectric layer on the solid acoustic mirror, and an interdigital transducer electrode on the piezoelectric layer. The interdigital transducer electrode is arranged to laterally excite a bulk acoustic wave.

A solidly mounted resonator having an electromagnetic shielding structure and a method for manufacturing the same. The solidly mounted resonator includes: a substrate; an acoustic-wave reflecting layer formed on the substrate; a resonance function layer formed on the acoustic-wave reflecting layer; and a metal shielding wall formed on the substrate, wherein the metal shielding wall surrounds an effective region in the acoustic-wave reflecting layer and the resonance function layer. The electromagnetic shielding structure is formed simultaneously with the resonator, and it is not necessary to provide an additional electromagnetic shielding device. An influence of an external or internal electromagnetic interference source on the resonator is avoided while ensuring a small dimension and a high performance of the resonator.

A piezoelectric resonator includes a first conductive layer, and a piezoelectric layer affixed to a first side of the first conductive layer. The piezoelectric resonator also includes a stair step frame structure affixed to a first side of the piezoelectric layer, and a second conductive layer, affixed to the first side of the piezoelectric layer and covering the stair step frame structure.

A filter device, an RF front-end device and a wireless communication device are provided. The filter device includes a substrate, a passive device and at least one resonance device, wherein the passive device has a first side and a second side opposite to the first side, the substrate is located on the first side, and the at least one resonance device is located on the second side. The RF filter device formed by integrating the resonance device (such as an SAW or BAW resonance device) and the passive device (such as an IPD) can broaden the pass-band width, has a high out-of-band rejection, and occupies less space in an RF front-end chip.

The present invention provides a preparation method of solid reflection-type bulk acoustic resonator, including the following steps: taking a piece of ion-implanted piezoelectric material, growing reflecting layers below the implantation face of the piezoelectric material and/or above the substrate, then taking a substrate, and bonding it to the piezoelectric material; heating the bonded intermediate product gained to strip the film from the piezoelectric material and growing an upper electrode on the stripped side of the piezoelectric material. According to the preparation method of solid reflection-type bulk acoustic resonator disclosed in the present invention, resonators with high strength and good performance can be prepared by using wafer bonding and lay transfer technique for preparing high-quality piezoelectric films and combining the solid reflecting layer structure.