A radio-frequency module includes a module substrate, an inductor, and an acoustic wave filter. The inductor overlaps at least a portion of the acoustic wave filter when seen in a plan view from the normal direction of the module substrate. The inductor includes first and second coils connected in series. Each of the first and second coils is a spiral or helical coil that is wound with more than one turn. At least a portion of the first coil overlaps the second coil when seen in a plan view from the normal direction of the module substrate. A direction of a magnetic field generated by the first coil is opposite to a direction of a magnetic field generated by the second coil.

Disclosed herein are embodiments of a ladder-type filter comprising a plurality of series arm resonators and a plurality of parallel arm resonators, at least one of the plurality of series arm resonators including a piezoelectric substrate and an interdigital transducer electrode disposed on the piezoelectric substrate, an aperture W1 of the interdigital transducer electrode being configured to be less than 13λ, where λ is a wavelength of a surface acoustic wave excited by the interdigital transducer electrode. The relationship between the aperture W1 and the wavelength λ can be W1 < 13λ, W1 < 11λ, W1 < 4λ, or W1 > 6λ.

A multiplexer includes acoustic wave filters that are electrically connected to a common connection terminal. In a first transmission-side filter of the acoustic wave filters, a series arm resonator closest to the common connection terminal includes acoustic wave resonators that are electrically connected in series and capacitance elements that are electrically connected between at least one of signal paths electrically connecting the acoustic wave resonators to each other and a reference terminal.

A multiplexer includes a transmission-side filter electrically connected to a common terminal and a transmission input terminal, and a transmission-side filter electrically connected to the common terminal and a transmission input terminal. The transmission-side filter includes a plurality of series arm resonators and a plurality of parallel arm resonators. Capacitance elements are respectively electrically connected in parallel to the series arm resonator and the parallel arm resonator, which are connected most proximately to the common terminal. IDT electrodes of a series arm resonator and a parallel arm resonator connected most proximately to the common terminal do not include a thinning electrode, and others of the series arm resonators and the parallel arm resonators include thinning electrodes.

An acoustic wave device includes a support substrate, a silicon nitride film stacked on the support substrate, a silicon oxide film stacked on the silicon nitride film, a piezoelectric body stacked on the silicon oxide film and made of lithium tantalite, and an IDT electrode provided on one main surface of the piezoelectric body. For a wavelength normalized film thickness of the piezoelectric body, an Euler angle of the piezoelectric body, a wavelength normalized film thickness of the silicon nitride film, a wavelength normalized film thickness of the silicon oxide film, and a wavelength normalized film thickness of the IDT electrode, values are set so that at least one of a response intensity of a first higher order mode, corresponding to the response intensity of a second higher order mode, and of a response intensity of a third higher mode is greater than about −2.4.

Embodiments disclosed herein include diagnostic substrates and methods of using the diagnostic substrates to extract plasma parameters. In an embodiment, a diagnostic substrate comprises a substrate and an array of resonators across the substrate. In an embodiment, the array of resonators comprises at least a first resonator with a first structure and a second resonator with a second structure. In an embodiment, the first structure is different than the second structure.

An elastic wave device includes a supporting substrate including an upper surface including a recessed portion, a piezoelectric thin film on the supporting substrate to cover the recessed portion of the supporting substrate, an IDT electrode on a main surface of the piezoelectric thin film, the main surface being adjacent to the supporting substrate, and an intermediate layer on a main surface of the piezoelectric thin film, the main surface being remote from the supporting substrate. A space is defined by the supporting substrate and the piezoelectric thin film. The IDT electrode faces the space. Through holes are provided in the piezoelectric thin film and the intermediate layer to extend from a main surface of the intermediate layer to the space, the main surface being remote from the piezoelectric thin film. The elastic wave device further includes a cover member on the intermediate layer and covering opening ends of the through holes.

The present invention relates to a surface acoustic wave device package and a method of manufacturing the same, and more specifically, to a method of manufacturing a miniaturized surface acoustic wave device package.

A method of manufacturing an acoustic wave device is disclosed. The method includes attaching a support layer to a ceramic layer. The support layer has a higher thermal conductivity than the ceramic layer. The ceramic layer can be a polycrystalline spinel layer. The method also includes bonding a piezoelectric layer to a surface of the ceramic layer. The method further includes forming an interdigital transducer electrode over the piezoelectric layer.

An acoustic wave element 1 according to the present disclosure includes a piezoelectric substrate 2 and an IDT electrode 3 on the piezoelectric substrate 2. The IDT electrode 3 includes a multilayer structure of a first layer 35 comprised of Al containing 10% or less of a sub-component and a second layer 37 comprised of a CuAl.sub.2 alloy. The second layer 37 enables the acoustic wave element 1 to have excellent electric power resistance.