Murata Manufacturing Co., Ltd.

Yasuharu Nakai

Michio Kadota

Takeshi Nakao

Katsuya Daimon

Kenji Nishiyama

Shunsuke Kido

Toshimaro Yoneda

Yasuhiro Kuratani

Akira Michigami

Masaharu Itaya

Hideaki Takahashi

Masako Tenpaku

Yoshifumi Wada

Hirokazu Sakaguchi

Yusuke Yoshida

Masako Miyoshi

A first filter of a multiplexer includes serial resonators and parallel resonators that are acoustic wave resonators. A first of the serial resonators that is closer to a common terminal than the other serial resonators is connected to the common terminal without the parallel resonators interposed therebetween. Each of the elastic wave resonators includes a substrate having piezoelectricity, an IDT electrode provided on the substrate, and a dielectric layer provided on the substrate to cover the IDT electrode. A thickness of the dielectric layer of the first serial resonator is smaller than a thickness of each of the dielectric layers of the remainder of the elastic wave resonators.

Multiplexer, high-frequency front-end circuit, and communication device

An elastic wave device includes a piezoelectric substrate, an IDT electrode on the piezoelectric substrate, and a silicon oxide film arranged on the piezoelectric substrate to cover the IDT electrode. The IDT electrode includes first and second electrode layers laminated on each other, the first electrode layer is made of metal or an alloy with a density higher than a density of metal of the second electrode layer and a density of silicon oxide of the silicon oxide film, the piezoelectric substrate is made of LiNbOand &#x3b8; is in a range of equal to or greater than about 8&#xb0; and equal to or less than about 32&#xb0; with Euler Angles (0&#xb0;&#xb1;5&#xb0;, &#x3b8;, 0&#xb0;&#xb1;10&#xb0;) of the piezoelectric substrate, and the silicon oxide film contains hydrogen atoms, hydroxyl groups, or silanol groups.

Elastic wave device, high-frequency front end circuit, and communication apparatus

An elastic wave device includes a piezoelectric substrate, elastic wave resonators on or in the piezoelectric substrate, and a dielectric film disposed on the piezoelectric substrate and covering the elastic wave resonators. The elastic wave resonators includes respective IDT electrodes on the piezoelectric substrate. When a wavelength specified by an electrode finger pitch of the IDT electrode is denoted as &#x3bb;, at least two of the elastic wave resonators have the different wavelengths. In two of the elastic wave resonators having different wavelengths, a film thickness of the IDT electrode in the elastic wave resonator having the longer wavelength is not greater than that of the IDT electrode in the elastic wave resonator having the shorter wavelength. Film thicknesses of the IDT electrodes in at least two of the elastic wave resonators are different from each other. The elastic wave device utilizes a Rayleigh wave.

Elastic wave device

A module includes a charging circuit and a driven unit. The charging circuit includes a power generation element and an electric storage element. The power generation element is connected to the electric storage element to charge the electric storage element. The electric storage element is connected to the driven unit to drive the driven unit with electric power stored. The power-generating voltage of the power generation element has a value equal to or more than the charging voltage of the electric storage element. The electric storage element is a secondary battery including a lithium-transition metal oxide in a positive electrode active material layer, and a lithium-titanium oxide of spinel-type crystal structure in a negative electrode active material layer.

Charging circuit and module using the same

A surface acoustic wave device includes a piezoelectric substrate, at least one interdigital transducer (IDT) electrode provided on the piezoelectric substrate, and an insulator layer to improve a temperature characteristic arranged so as to cover the IDT electrode. When a surface of the insulator layer is classified into a first surface region under which the IDT electrode is positioned and a second surface region under which no IDT electrode is positioned, the surface of the insulator layer in at least one portion of the second surface region is higher than the surface of the insulator layer from the piezoelectric substrate in at least one portion of the first surface region by at least about 0.001&#x3bb;, where the wavelength of an acoustic wave is &#x3bb;.

Acoustic wave device and method for fabricating the same

A method for fabricating an acoustic wave device includes the steps of forming an insulating material layer on a piezoelectric substrate, forming a patterned photoresist on the insulating material layer, patterning the insulating material layer, and forming a piezoelectric-substrate exposed depression corresponding to a region where an interdigital transducer electrode is to be formed on a first insulator layer composed of the insulating material layer, depositing a metallic material on the piezoelectric substrate to form the interdigital transducer electrode in the piezoelectric-substrate exposed depression such that the overall interdigital transducer electrode is thinner than the first insulator layer and coating the photoresist with a metallic material, removing the photoresist and the metallic material on the photoresist, and depositing a second insulator layer so as to cover the interdigital transducer electrode and the first insulator layer.

Method for fabricating acoustic wave device

In an acoustic wave resonator, an IDT electrode is provided on a piezoelectric substrate. The IDT electrode is apodization-weighted such that a plurality of maximum values of cross widths are provided in acoustic wave propagation directions. Alternatively, in apodization weighting, weighting is applied such that at least one of a pair of envelopes located at outer side portions of the IDT electrode in directions substantially perpendicular to acoustic wave propagation directions includes a plurality of angled envelope portions angled from a central portion of the IDT electrode toward an outer side portion of the IDT electrode in a direction substantially perpendicular to the acoustic wave propagation directions.

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Takatsuki, Japan

Yasuharu Nakai