An elastic wave device includes a supporting substrate, an acoustic multilayer film on the supporting substrate, a piezoelectric substrate on the acoustic multilayer film, and an IDT electrode on the piezoelectric substrate. The acoustic multilayer film includes at least four acoustic impedance layers. The at least four acoustic impedance layers include at least one low acoustic impedance layer and at least one high acoustic impedance layer having an acoustic impedance higher than the low acoustic impedance layer. The elastic wave device further includes a bonding layer provided at any position in a range of from inside the acoustic impedance layer, which is the fourth acoustic impedance layer from the piezoelectric substrate side towards the supporting substrate side, to an interface between the acoustic multilayer film and the supporting substrate.

An acoustic wave device includes a piezoelectric substrate and an IDT electrode directly or indirectly disposed on the piezoelectric substrate. The IDT electrode includes first metal layers, a second metal layer disposed on one of the first metal layers, and a third metal layer disposed on the second metal layer. The first, second, and third metal layers include side surfaces, respectively. The side surface includes a first end portion adjacent to the second metal layer. The side surface includes a second end portion adjacent to the second metal layer. In at least a portion of the IDT electrode, a creepage distance stretching from the first end portion to the second end portion via the side surface of the second metal layer is longer than a distance between the first end portion and the second end portion.

An acoustic wave device includes a high-acoustic-velocity support substrate, a low-acoustic-velocity film provided on the high-acoustic-velocity support substrate, a piezoelectric layer provided on the low-acoustic-velocity film, and an IDT electrode provided on the piezoelectric layer. An acoustic velocity of a bulk wave propagating through the high-acoustic-velocity support substrate is higher than an acoustic velocity of an acoustic wave propagating through the piezoelectric layer. An acoustic velocity of a bulk wave propagating through the low-acoustic-velocity film is lower than an acoustic velocity of a bulk wave propagating through the piezoelectric layer. The low-acoustic-velocity film has a first portion and a second portion that is located closer to the high-acoustic-velocity support substrate than the first portion. The first and second portions include the same or similar materials. A density in the first portion of the low-acoustic-velocity film and a density in the second portion of that are different.

An acoustic wave filter includes at least three segmented resonator devices connected in series to one another and aligned in a direction that crosses an acoustic wave propagation direction and each including an InterDigital Transducer (IDT) electrode, and centers of respective IDT electrodes of an adjacent pair of the at least three segmented resonator devices in the acoustic wave propagation direction are not aligned when seen from a direction orthogonal to the acoustic wave propagation direction.

An apparatus is disclosed for suspending an electrode structure using a dielectric. In an example aspect, the apparatus includes a surface-acoustic-wave filter with a piezoelectric layer and an electrode structure. The electrode structure has a first surface facing the piezoelectric layer and separated from the piezoelectric layer by a distance. The surface-acoustic-wave filter also includes a dielectric disposed on at least one other surface of the electrode structure and configured to extend past a plane defined by the first surface of the electrode structure and toward the piezoelectric layer to define a cavity between at least a portion of the first surface of the electrode structure and the piezoelectric layer.

A filter device includes a first filter and a second filter. The first filter and the second filter are disposed in parallel between a first terminal and a second terminal. A first passband of the filter device includes at least part of a second passband of the first filter. The first passband includes at least part of a third passband of the second filter. The second passband is narrower than the first passband. The third passband is narrower than the first passband. The third passband has a center frequency higher than a center frequency of the second passband. The first filter includes multiple elastic wave resonators and a first capacitive element. The first capacitive element is connected in parallel with the first elastic wave resonator.

An improved SAW (SAWR) resonator having an improved power durability and heat resistance and a protection to prevent device failure is provided. The SAW resonator has a carrier substrate (S) and an electrode structure (ES, EF) on a piezoelectric material (PM, PL). Further, the resonator has a shunt path (PCPP) parallel to the electrode structure and provided to enable an RF signal to bypass the electrode structure. The shunt path has a temperature dependent conductance with negative temperature coefficient of resistance.

An elastic wave device using the S0 mode of plate waves includes a support substrate, an acoustic reflective layer laminated on the support substrate, a piezoelectric body laminated on the acoustic reflective layer, and an IDT electrode disposed on the piezoelectric body. In the acoustic reflective layer, T1+T2 is between about 0.40 and about 0.60 inclusive in a portion in which low and high acoustic impedance layers are adjacent in the laminating direction. T1 is the thickness of the low acoustic impedance layers. T2 is the thickness of the high acoustic impedance layers. T1/(T1+T2) is between about 0.35 and about 0.65 inclusive.

An acoustic wave device comprises a substrate including a piezoelectric material, interdigital transducer (IDT) electrodes including interdigitated electrode fingers disposed on a surface of the substrate, and a passivation layer formed on tops of the IDT electrodes and on the piezoelectric material in gaps between adjacent IDT electrodes, the passivation film being thicker on the tops of the IDT electrodes than on the piezoelectric material in the gaps between adjacent IDT electrodes to improve an electromechanical coupling factor of the acoustic wave device.

A method for manufacturing a structure comprising a thin layer transferred onto a support provided with a charge trapping layer, the method comprising the following steps: —preparing the support comprising forming the trapping layer on a base substrate, the trapping layer having a hydrogen concentration of less than 10{circumflex over ( )}18 at/cm{circumflex over ( )}; —joining the support to a donor substrate by way of a dielectric layer having a hydrogen concentration of less than 10{circumflex over ( )}20 at/cm{circumflex over ( )}3 or comprising a barrier preventing the diffusion of hydrogen toward the trapping layer or having low hydrogen diffusivity; —removing part of the donor substrate to form the thin layer; the manufacturing method exposing the structure to a temperature below a maximum temperature of 1000° C. The present disclosure also relates to a structure obtained at the end of this method.