An RF filter comprising a resonator element and a polymer composition is provided. The polymer composition contains an aromatic polymer and has a melting temperature of about 240° C. or more. The polymer composition exhibits a dielectric constant of about 5 or less and dissipation factor of about 0.05 or less at a frequency of 10 GHz.

An acoustic wave device includes a piezoelectric layer and first and second electrodes. The first and second electrodes face each other in a direction intersecting with a thickness direction of the piezoelectric layer. The acoustic wave device uses a bulk wave of a thickness-shear primary mode. A material of the piezoelectric layer is lithium niobate or lithium tantalate. The piezoelectric layer is on a first main surface of the silicon substrate. The acoustic wave device further includes a trap region on a side of a second main surface of the piezoelectric layer.

The present application provides a resonator and a method of preparing same, and relates to the field of semiconductor technologies. The method includes: providing a device wafer, wherein the device wafer includes a first substrate and a piezoelectric layer, a bottom electrode, and a first mass loading layer formed in sequence on the first substrate; forming, on the bottom electrode, a sacrificial layer covering the first mass loading layer; forming a supporting layer on one side of the device wafer with the sacrificial layer; forming a second substrate on the supporting layer through a bonding process; removing the first substrate to expose the piezoelectric layer; forming a top electrode and a second mass loading layer in sequence on the piezoelectric layer; and releasing the sacrificial layer to form a cavity between the first mass loading layer and the supporting layer. Therefore, the resonator is correspondingly tuned by controlling a ratio of an area of the first mass loading layer in an effective working region of the resonator to an area of the second mass loading layer in the effective working region of the resonator, thereby manufacturing resonators with different resonant frequencies, effectively avoiding loss caused by tuning with an external element, and ensuring good performance of the resonator.

Acoustic resonator devices and filters are disclosed. An acoustic resonator includes a substrate and a piezoelectric plate having parallel front and back surfaces. The substrate includes a silicon base having a trap-rich region adjacent to a surface and a dielectric layer on the surface. The back surface of the piezoelectric plate faces the dielectric layer. The piezoelectric plate comprises a diaphragm that spans a cavity in the substrate. An interdigital transducer (IDT) is provided on the front surface of the piezoelectric plate such that interleaved fingers of the IDT are on the diaphragm.

Embodiments of this disclosure relate to bulk acoustic wave resonators on a substrate. The bulk acoustic wave resonators include a first bulk acoustic wave resonator, a second bulk acoustic wave resonator, a conductor electrically connecting the first bulk acoustic wave resonator to the second bulk acoustic wave resonator, and an air gap positioned between the conductor and a surface of the substrate.

An example integrated circuit package includes an acoustic wave resonator, the acoustic wave resonator including a Fresnel surface. In some examples, the Fresnel surface includes a plurality of recessed features and/or protruding features at different locations on the Fresnel surface, each of the plurality of features to confine main mode acoustic energy from a respective portion of the Fresnel surface in a central portion of the acoustic wave resonator.

An electro acoustic filter component with improved acoustic and/or electro acoustic performance is provided. The component comprises a piezoelectric material (PM) the sides of which are plane and preferably free from chipping defects. The piezoelectric material may be arranged above a carrier substrate (CS). A functional layer (FL) with plane sides may be arranged above an electrode structure (ES) as trimming, TCF or passivation layer. In the manufacturing method the piezoelectric material and the functional layer are removed from the dicing line, such that no chipping occurs for these layers.

An acoustic wave device includes a piezoelectric layer and first and second electrodes. The first and second electrodes face each other in a direction intersecting with a thickness direction of the piezoelectric layer. The acoustic wave device uses a bulk wave of a thickness-shear primary mode. A material of the piezoelectric layer is lithium niobate or lithium tantalate. The piezoelectric layer is on a first main surface of the silicon substrate. The acoustic wave device further includes a trap region on a side of a second main surface of the piezoelectric layer.

Embodiments of this disclosure relate to acoustic wave filters configured to filter radio frequency signals. An acoustic wave filter includes a first bulk acoustic wave resonator on a substrate, a second bulk acoustic wave resonator on the substrate, a conductor electrically connecting the first bulk acoustic wave resonator in anti-series with the second bulk acoustic wave resonator, and an air gap positioned between the conductor and a surface of the substrate. The air gap can reduce parasitic capacitance associated with the conductor. Acoustic wave filters disclosed herein can suppress a second harmonic.

The disclosure relates to a hybrid structure for a surface-acoustic-wave device comprising a useful layer of piezoelectric material joined to a carrier substrate having a thermal expansion coefficient lower than that of the useful layer; the hybrid structure comprising an intermediate layer located between the useful layer and the carrier substrate, the intermediate layer being a structured layer formed from at least two different materials comprising a plurality of periodic motifs in the plane of the intermediate layer.