A SAW transducer and a SAW resonator are proposed composed of consecutively arranged unit cells of length L. Slight geometry or material variations such as variations of the metallization ration or the unit cell length L affecting the pitch) between these unit cells result in improved spurious mode suppression while the main mode performance is unaffected.

A surface acoustic wave (SAW) device comprises a substrate and composite electrodes. The composite electrodes comprise a metal layer and a graphene layer. The SAW device may be used to satisfy requirements for the fifth generation (5G) mobile communication.

A SAW transducer and a SAW resonator are proposed composed of consecutively arranged unit cells of length L. Slight geometry or material variations such as variations of the metallization ration or the unit cell length L affecting the pitch) between these unit cells result in improved spurious mode suppression while the main mode performance is unaffected.

An acoustic wave device includes a support including a support substrate, a piezoelectric layer on the support, and an IDT electrode including busbars and electrode fingers, and a mass-adding film on the piezoelectric layer. In plan view as seen in a stacking direction in which the support and the piezoelectric layer are stacked, an acoustic reflector overlaps at least a portion of the IDT electrode. d/p is less than or equal to about 0.5, where d is a thickness of the piezoelectric layer and p is a center-to-center distance between adjacent electrode fingers. A region in which adjacent electrode fingers overlap each other when seen from an electrode-finger-facing direction is a crossing region. Regions between the crossing region and the pair of busbars include first and second gap regions. The mass-adding film overlaps the gap region in plan view and is on the second main surface of the piezoelectric layer.

An elastic wave element has a piezoelectric substrate; an excitation electrode which is located on an upper surface of the piezoelectric substrate and generates an acoustic wave, and two reflectors which are located on the upper surface of the piezoelectric substrate and sandwich the excitation electrode in the propagation direction of the acoustic wave. The excitation electrode has a main region located between the two end parts of the propagation direction and outer regions located on two sides of the main region. When the number of the electrode fingers of the outer region is m, an electrode finger interval of the main region is a, and an interval between the electrode finger of the main region on the outer region side and the reflector electrode finger of the reflector is x, 0.5a(m+1)<x<a(m+1) is satisfied. Further, a resonant frequency of the reflector is lower than a resonant frequency in the main region of the excitation electrode.

The present invention relates to a one-port resonator (1) operating with surface acoustic waves, comprising an interdigital transducer (2) having a first busbar (6), a second busbar (7) and electrode fingers (8), wherein in an excitation region (10) of the interdigital transducer (2) the electrode fingers (8) are alternately connected to the first busbar (6) and the second busbar (7) in the longitudinal direction (L), wherein the interdigital transducer (2) comprises a first reversed region (11), in which the electrode fingers (8) are alternately connected to the first busbar (6) and the second busbar (7) in the longitudinal direction (L) and which is directly adjacent to the excitation region (10), and wherein that electrode finger (118) of the first reversed region (11) which is directly adjacent to the excitation region (10) in the longitudinal direction (L) and that electrode finger (118) of the excitation region (10) which is directly adjacent thereto are connected to the same busbar (6, 7).

An acoustic wave device includes a piezoelectric layer, and a pair of interdigital electrodes provided on the piezoelectric layer. Each of the pair of interdigital electrodes has electrode fingers and a bus bar to which the electrode fingers are connected. An intersection region where the electrode fingers intersect each other includes an edge region, a central region, and an intermediate region located between the edge region and the central region. When a weight per unit length in the longitudinal direction of a single-layer or multilayer film including a metal layer of at least one of the electrode fingers provided on the piezoelectric layer is a first weight in the central region, a second weight in the intermediate region, and a third weight in the edge region, the second weight is larger than the first weight and the third weight is smaller than the first weight.