Murata Manufacturing Co., Ltd.

Murata Manufacturingco., Ltd.

Masakazu Mimura

Michio Kadota

Takeshi Nakao

Yasumasa Taniguchi

Hajime Kando

Katsuya Daimon

Kazuhiro Takigawa

Masato Araki

Daisuke Tamazaki

Yutaka Kishimoto

Yasuhisa Fujii

Hideya Horiuchi

Norio Taniguchi

Taku Kikuchi

Junya Ago

Masaru Yata

Yasuhiro Kuratani

Norihiko Nakahashi

Hiroshi Muranaka

Tomohisa Komura

Daisuke Fukuda

Akira Konno

A surface acoustic wave device includes a piezoelectric substrate made of θ° rotated Y-cut X-propagation LiNbOhaving a cut angle θ, an IDT electrode on the piezoelectric substrate and including a plurality of electrode fingers, and a dielectric film on the piezoelectric substrate and covering the IDT electrode. The IDT electrode includes a main electrode layer and an auxiliary conductive layer. The main electrode layer is, compared to the auxiliary conductive layer, closer to a side of the piezoelectric substrate. The main electrode layer includes Pt as a main component. Where the film thickness of the main electrode layer is denoted as h, the film thickness of the dielectric film is denoted as H, and a wavelength determined by the electrode finger pitch of the IDT electrode is denoted as λ, the relationship in Formula (1) and Equation (2A) to Equation (2D) is satisfied.

Surface acoustic wave device and filter device

An acoustic wave device includes a piezoelectric substrate made of LiNbO, and a dielectric film provided on the piezoelectric substrate to cover first and second IDT electrodes on the piezoelectric substrate. The first and second IDT electrodes include main electrode layers. When wave lengths determined by electrode finger pitches of the first and second IDT electrodes are λand λ, respectively, the average value thereof is λ, λ/λ=1+X, and λ/λ=1−X, a relationship of 0.05≤X≤0.65 is satisfied. The wavelength λis the longest, and the wavelength λis the shortest. In Euler angles (φ, θ, ψ) of the piezoelectric substrate, φ is 0°±5°, ψ is 0°±10°, and θ satisfies Expression 1, wherein a relationship of B<T×r≤0.10λand B<T×r≤0.10λare satisfied.

Acoustic wave device, high frequency front end circuit, and communication apparatus

A bandpass acoustic wave filter device includes an IDT electrode and a dielectric film disposed on a piezoelectric substrate including a LiNbOlayer, and an acoustic wave resonator is defined by the IDT electrode. The acoustic wave resonator utilizes the Rayleigh wave, and a response of an SH wave excited by the acoustic wave resonator is outside a pass band of the acoustic wave filter device.

Acoustic wave filter device

A composite filter device includes a piezoelectric substrate made of LiNbO, a first filter on the piezoelectric substrate, and including acoustic wave resonators, and a second filter including one end connected in common to one end of the first filter, wherein a pass band of the second filter is in a frequency band higher than a pass band of the first filter, and bulk wave radiation frequencies of all of the first and second resonators of the first filter are higher than the pass band of the second filter.

Composite filter device

An elastic wave device includes an interdigital transducer electrode, a dielectric film, and a frequency adjustment film are disposed on a LiNbOsubstrate. When Euler Angles of the LiNbOsubstrate are within a range of about 0°±5°, within a range of about θ±1.5°, within a range of about 0°±10°, the interdigital transducer electrode includes a main electrode, a film thickness of the main electrode normalized by a wavelength determined in accordance with an electrode finger pitch of the interdigital transducer electrode is denoted as T, and a density ratio of a material of the main electrode to Pt is denoted as r, the film thickness of the main electrode and θ of the Euler Angles satisfy θ=−0.05°/(T/r−0.04)+31.35°.

Elastic wave device

An elastic wave device includes an LiNbOsubstrate, a first elastic wave resonator including a first IDT electrode and a first dielectric film, and a second elastic wave resonator including a second IDT electrode and a second dielectric film. A Rayleigh wave travels along at least one surface of the elastic wave device. A thickness of the first dielectric film differs from a thickness of the second dielectric film. A propagation direction of an elastic wave in the first elastic wave resonator coincides with a propagation direction of an elastic wave in the second elastic wave resonator. Euler angles of the LiNbOsubstrate fall within a range of (0°±5°, θ, 0°±10°).

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

An acoustic wave device includes a piezoelectric substrate made of LiNbO, and a dielectric film provided on the piezoelectric substrate to cover first and second IDT electrodes on the piezoelectric substrate. The first and second IDT electrodes include main electrode layers. When wave lengths determined by electrode finger pitches of the first and second IDT electrodes are &#x3bb;and &#x3bb;, respectively, the average value thereof is &#x3bb;, &#x3bb;/&#x3bb;=1+X, and &#x3bb;/&#x3bb;=1&#x2212;X, a relationship of 0.05&#x2264;X&#x2264;0.65 is satisfied. The wavelength &#x3bb;is the longest, and the wavelength &#x3bb;is the shortest. In Euler angles (&#x3c6;, &#x3b8;, &#x3c8;) of the piezoelectric substrate, &#x3c6; is 0&#xb0;&#xb1;5&#xb0;, &#x3c8; is 0&#xb0;&#xb1;10&#xb0;, and &#x3b8; satisfies Expression 1, wherein a relationship of B&#x3c;T&#xd7;r&#x2264;0.10&#x3bb;and B&#x3c;T&#xd7;r&#x2264;0.10&#x3bb;are satisfied.

An acoustic wave device includes a piezoelectric substrate and an IDT electrode provided on the piezoelectric substrate and includes a main electrode layer. In the IDT electrode, a central region, first and second low acoustic velocity regions and first and second high acoustic velocity regions are disposed in this order. A duty ratio in the first low acoustic velocity region of first electrode fingers and the second low acoustic velocity region of second electrode fingers is larger than a duty ratio in the central region. The main electrode layer includes any one of Au, Pt, Ta, Cu, Ni, and Mo as a main component.

Acoustic wave device, high-frequency front end circuit, and communication device

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.

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

An elastic wave device includes an interdigital transducer electrode, a dielectric film, and a frequency adjustment film are disposed on a LiNbOsubstrate. When Euler Angles of the LiNbOsubstrate are within a range of about 0&#xb0;&#xb1;5&#xb0;, within a range of about &#x3b8;&#xb1;1.5&#xb0;, within a range of about 0&#xb0;&#xb1;10&#xb0;, the interdigital transducer electrode includes a main electrode, a film thickness of the main electrode normalized by a wavelength determined in accordance with an electrode finger pitch of the interdigital transducer electrode is denoted as T, and a density ratio of a material of the main electrode to Pt is denoted as r, the film thickness of the main electrode and &#x3b8; of the Euler Angles satisfy &#x3b8;=&#x2212;0.05&#xb0;/(T/r&#x2212;0.04)+31.35&#xb0;.

An elastic wave device includes a supporting substrate, an acoustic reflection layer on the supporting substrate, a piezoelectric layer on the acoustic reflection layer, and an IDT electrode on the piezoelectric layer. The acoustic reflection layer includes three or more low-acoustic impedance layers and two or more high-acoustic impedance layers. At least one of a first relationship in which in which, a film thickness of a first low-acoustic impedance layer closest to the piezoelectric layer is thinner than a film thickness of a low-acoustic impedance layer closest to the first low-acoustic impedance layer, and a second relationship in which a film thickness of a first high-acoustic impedance layer closest to the piezoelectric layer is thinner than a film thickness of a high-acoustic impedance layer closest to the first high-acoustic impedance layer, is satisfied.

An acoustic wave device includes a piezoelectric body made of lithium niobate and disposed directly or indirectly on a supporting substrate, and IDT electrode disposed directly or indirectly on the piezoelectric body. When the wavelength of an acoustic wave that is determined by a pitch of electrode fingers of the IDT electrode is denoted by &#x3bb;, the thickness of the piezoelectric body is equal to or less than about 1&#x3bb;. The acoustic wave device uses the plate wave S0 mode propagating in the piezoelectric body. The Euler angles of the lithium niobate are (0&#xb0;&#xb1;10&#xb0;, &#x3b8;, 90&#xb0;&#xb1;10&#xb0;), provided that &#x3b8; is from about 0&#xb0; to about 180&#xb0; inclusive.

Acoustic wave device

An elastic wave device includes an LiNbOsubstrate, a first elastic wave resonator including a first IDT electrode and a first dielectric film, and a second elastic wave resonator including a second IDT electrode and a second dielectric film. A Rayleigh wave travels along at least one surface of the elastic wave device. A thickness of the first dielectric film differs from a thickness of the second dielectric film. A propagation direction of an elastic wave in the first elastic wave resonator coincides with a propagation direction of an elastic wave in the second elastic wave resonator. Euler angles of the LiNbOsubstrate fall within a range of (0&#xb0;&#xb1;5&#xb0;, &#x3b8;, 0&#xb0;&#xb1;10&#xb0;).

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Nagaokakyo, Japan

Masakazu Mimura