Abstract: A preparation method, a product and an application of a composite membrane with a self-repairing function are provided by the present application, relating to the technical field of surface treatment of metallic materials. The preparation method includes the following steps: adding cobalt salt, tungsten salt, complexing agent and buffering agent into water to obtain a mixed solution, and adjusting a pH value to acidity to obtain an acidic solution; adding cerium oxide and surfactant into the acidic solution to obtain an electrolyte system; and placing a metal substrate in the electrolyte system for electrodeposition to obtain the composite membrane with self-repairing function. By means of constant potential composite electrodeposition on a metallic material substrate, the invention eventually forms a micron-scale composite membrane with a self-healing function and a thickness of 6-8 micrometers on the surfaces of the metallic materials.

Abstract: Embodiments of this application provide a bulk acoustic resonator, an acoustic filter, and an electronic device, to improve performance of the acoustic filter. The bulk acoustic resonator includes a piezoelectric material layer, an interdigital transducer, and a dielectric layer. The interdigital transducer is disposed on the piezoelectric material layer. The interdigital transducer includes a first busbar and a second busbar that are disposed opposite to each other, a plurality of first electrodes, and a plurality of second electrodes. The plurality of first electrodes sequentially protrude from the first busbar to the second busbar along an extension direction of the first busbar. The plurality of second electrodes sequentially protrude from the second busbar to the first busbar along an extension direction of the second busbar. The plurality of first electrodes and the plurality of second electrodes are sequentially arranged in a staggered manner between the first busbar and the second busbar.

Abstract: An acoustic filter includes a first resonator, a second resonator, and a first acoustic wave suppression structure. The first resonator and the second resonator are arranged in a first direction. The first acoustic wave suppression structure is disposed between the first resonator and the second resonator, and at least one stopband generated by the first acoustic wave suppression structure is used to reduce an acoustic wave that is leaked between the first resonator and the second resonator and that is propagated in the first direction.

Abstract: A bulk acoustic wave resonator comprises a piezoelectric material layer, a first comb-shaped electrode, a second comb-shaped electrode, and at least one grid structure. The first comb-shaped electrode is disposed on the piezoelectric material layer, and the first comb-shaped electrode includes a first busbar and a plurality of first electrode fingers sequentially arranged along an extension direction of the first busbar. The second comb-shaped electrode is disposed on the piezoelectric material layer, and the second comb-shaped electrode includes a second busbar and a plurality of second electrode fingers sequentially arranged along an extension direction of the second busbar. The plurality of first electrode fingers and the plurality of second electrode fingers are arranged at spacings and do not contact each other. The grid structure is disposed at least between the first electrode finger and the second electrode finger.

Abstract: Aspects of this disclosure relate to a bulk acoustic wave device with a multi-layer raised frame. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-layer raised frame structure configured to cause lateral energy leakage from a main acoustically active region of the bulk acoustic wave device to be reduced. The multi-layer raised frame structure includes a first raised frame layer embedded in the piezoelectric layer and a second raised frame layer. The first raised frame layer has a lower acoustic impedance than the piezoelectric layer.

Abstract: Aspects of this disclosure relate bulk acoustic wave resonators with a patterned mass loading layer at least contributing to a difference in mass loading between a main acoustically active region of the bulk acoustic wave resonator and a recessed frame region of the bulk acoustic wave resonator. Related methods of manufacturing can involve forming the patterned mass loading layer in the main acoustically active region and the recessed frame region in a common processing step such that the patterned mass loading layer has a higher density in the main acoustically active region than in the recessed frame region.

Abstract: Aspects of this disclosure relate to bulk acoustic wave resonators with patterned mass loading layers. Two different bulk acoustic wave resonators of an acoustic wave filter and/or an acoustic wave die have respective patterned mass loading layers with different densities. The patterned mass loading layers contribute to the two different bulk acoustic wave resonators having different respective resonant frequencies. Related bulk acoustic wave devices, filters, acoustic wave dies, radio frequency modules, wireless communication devices, and methods are disclosed.

Abstract: Aspects of this disclosure relate to bulk acoustic wave resonators with patterned mass loading layers. Two different bulk acoustic wave resonators of an acoustic wave filter and/or an acoustic wave die have respective patterned mass loading layers with different densities. The patterned mass loading layers contribute to the two different bulk acoustic wave resonators having different respective resonant frequencies. Related bulk acoustic wave devices, filters, acoustic wave dies, radio frequency modules, wireless communication devices, and methods are disclosed.

Abstract: Aspects of this disclosure relate to bulk acoustic wave resonators. A bulk acoustic wave resonator includes a patterned mass loading layer that affects a resonant frequency of the bulk acoustic wave resonator. The patterned mass loading layer can have a duty factor in a range from 0.2 to 0.8 in a main acoustically active region of the bulk acoustic wave resonator. Related filters, acoustic wave dies, radio frequency modules, wireless communications devices, and methods are disclosed.

Abstract: Aspects of this disclosure relate to methods of manufacturing bulk acoustic wave resonators. During a common processing step, a first patterned mass loading layer for a first bulk acoustic wave resonator is formed and a second patterned mass loading layer for a second bulk acoustic wave resonator is formed. The first patterned mass loading layer has a different density than the second patterned mass loading layer.

Abstract: Aspects of this disclosure relate to bulk acoustic wave resonators with patterned mass loading layers. Two different bulk acoustic wave resonators of an acoustic wave filter and/or an acoustic wave die have respective patterned mass loading layers with different densities. The patterned mass loading layers contribute to the two different bulk acoustic wave resonators having different respective resonant frequencies. Related bulk acoustic wave devices, filters, acoustic wave dies, radio frequency modules, wireless communication devices, and methods are disclosed.

Abstract: Aspects of this disclosure relate bulk acoustic wave resonators with a patterned mass loading layer at least contributing to a difference in mass loading between a main acoustically active region of the bulk acoustic wave resonator and a recessed frame region of the bulk acoustic wave resonator. Related methods of manufacturing can involve forming the patterned mass loading layer in the main acoustically active region and the recessed frame region in a common processing step such that the patterned mass loading layer has a higher density in the main acoustically active region than in the recessed frame region.

Abstract: Aspects of this disclosure relate to bulk acoustic wave resonators. A bulk acoustic wave resonator includes a patterned mass loading layer that affects a resonant frequency of the bulk acoustic wave resonator. The patterned mass loading layer can have a duty factor in a range from 0.2 to 0.8 in a main acoustically active region of the bulk acoustic wave resonator. Related filters, acoustic wave dies, radio frequency modules, wireless communications devices, and methods are disclosed.

Abstract: Aspects of this disclosure relate to a bulk acoustic wave device with a multi-gradient raised frame. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-gradient raised frame structure configured to cause lateral energy leakage from a main acoustically active region of the bulk acoustic wave device to be reduced. The multi-gradient raised frame structure is tapered on opposing sides.

Abstract: Aspects of this disclosure relate to a bulk acoustic wave device with a multi-gradient raised frame. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-gradient raised frame structure. The multi-gradient raised frame structure includes a first raised frame layer and a second raised frame layer. The second raised frame layer extends beyond the first raised frame layer. The second raised frame layer is tapered on opposing sides.

Abstract: Aspects of this disclosure relate to a bulk acoustic wave device with a multi-layer raised frame. The bulk acoustic wave device includes a first electrode, a second electrode, a piezoelectric layer positioned between the first electrode and the second electrode, and a multi-layer raised frame structure configured to cause lateral energy leakage from a main acoustically active region of the bulk acoustic wave device to be reduced. The multi-layer raised frame structure includes a first raised frame layer embedded in the piezoelectric layer and a second raised frame layer. The first raised frame layer has a lower acoustic impedance than the piezoelectric layer.