Abstract: A surface acoustic wave resonator, a filter and a communication device are provided. The surface acoustic wave resonator includes a piezoelectric material layer, an interdigital transducer and a reflective electrode structure; the piezoelectric material layer includes a first region and two second regions arranged in a first direction; the interdigital transducer is located at a side of the piezoelectric material layer; the reflective electrode structure is arranged in the same layer as the interdigital transducer; the first region is located between two second regions, the interdigital transducer is located in the first region, the reflective electrode structure is located in the second region, and the surface acoustic wave resonator further includes a groove located in the piezoelectric material layer, the groove is located in the second region, and is located at a side of the reflective electrode structure away from the interdigital transducer in the first direction.

Abstract: A surface acoustic wave resonator, a filter, a manufacturing method thereof and a communication device. The surface acoustic wave resonator includes a piezoelectric material layer, an interdigital transducer and a dielectric layer; the interdigital transducer is located at a side of the piezoelectric material layer, and the dielectric layer is located between the interdigital transducer and the piezoelectric material layer. Therefore, the surface acoustic wave resonator can reduce the electromechanical coupling coefficient of the surface acoustic wave resonator by arranging the dielectric layer between the interdigital transducer and the piezoelectric material layer. In addition, the surface acoustic wave resonator can adjust the electromechanical coupling coefficient of the surface acoustic wave resonator by controlling the thickness of the dielectric layer.

Abstract: Provided is a method of manufacturing a bulk acoustic wave resonator, which includes: providing a piezoelectric substrate for forming a piezoelectric layer; forming a first electrode structure on the portion of the piezoelectric substrate for forming the piezoelectric layer; forming a dielectric layer on the first electrode structure, and performing a patterning process on the dielectric layer to form a patterned dielectric layer comprising a sacrificial dielectric part and a periphery dielectric part; forming a boundary layer on the patterned dielectric layer, the boundary layer covering a surface of the patterned dielectric layer and surrounding the sacrificial dielectric part; thinning the piezoelectric substrate to form the piezoelectric layer, the first electrode structure being located at a first side of the piezoelectric layer; forming a second electrode structure on a second side of the piezoelectric layer; and removing the sacrificial dielectric part to form a resonant cavity.

Abstract: Provided is a method of manufacturing a bulk acoustic wave resonator, which includes: providing a piezoelectric substrate for forming a piezoelectric layer; forming a first electrode structure on the portion of the piezoelectric substrate for forming the piezoelectric layer; forming a dielectric layer on the first electrode structure, and performing a patterning process on the dielectric layer to form a patterned dielectric layer comprising a sacrificial dielectric part and a periphery dielectric part; forming a boundary layer on the patterned dielectric layer, the boundary layer covering a surface of the patterned dielectric layer and surrounding the sacrificial dielectric part; thinning the piezoelectric substrate to form the piezoelectric layer, the first electrode structure being located at a first side of the piezoelectric layer; forming a second electrode structure on a second side of the piezoelectric layer; and removing the sacrificial dielectric part to form a resonant cavity.

Abstract: A bulk acoustic wave filter, a manufacturing method thereof, and a communication device are disclosed. The bulk acoustic wave filter includes a first filter substrate and a second filter substrate; the first filter substrate includes a first base substrate and a first resonator, a first electrode pad and a first auxiliary pad arranged on the first base substrate; the second filter substrate includes a second base substrate and a second resonator, a second electrode pad and a second auxiliary pad arranged on the second base substrate, the first filter substrate is arranged opposite to the second filter substrate, the first electrode pad and the second auxiliary pad are in contact with each other, and the second electrode pad and the first auxiliary pad are in contact with each other.

Abstract: An electrode structure of a resonator and a fabrication method for the electrode structure of the resonator are provided. The electrode structure includes a piezoelectric layer. An electrode metal layer, a dielectric layer, a protrusion/frame metal layer and an etching passivation layer are sequentially arranged above the piezoelectric layer. An air gap is formed between the dielectric layer and the protrusion/frame metal layer, and the air gap is located at an electrode edge. Through the air gap between the dielectric layer and the protrusion/frame metal layer above the piezoelectric layer, an electrode protrusion/frame structure of the resonator with an edge air gap is formed, which serves as an electrode part. When the resonator is working, through the air gap, a transverse sound wave can be reflected back to the resonator and be bound in a resonator body. This greatly increases the Q factor and working performance of the resonator.

Abstract: A bulk acoustic wave resonator and a bulk acoustic wave filter are provided. The bulk acoustic wave resonator includes: a piezoelectric layer; an electrode layer located at both sides of the piezoelectric layer; and an electrode edge frame structure located at an edge of the electrode layer and located at one side of the electrode layer away from the piezoelectric layer. The electrode edge frame structure includes a laminated structure, the laminated structure includes an edge convex layer and a passivation layer laminated in a longitudinal direction, and the passivation layer is located at one side of the edge convex layer away from the piezoelectric layer; in a transverse direction, the laminated structure includes a cantilever member and a convex structure connected with each other; a cantilever gap is arranged between the cantilever member and at least one of the piezoelectric layer and the electrode layer.