Murata Manufacturing Co., Ltd.

Ryo Nakagawa

Hideki Iwamoto

Tsutomu Takai

Takashi Yamane

Shou Nagatomo

Masashi Tsubokawa

Chihiro Konoma

Masanori Otagawa

Haruki Kyouya

Hiroshi Shimizu

Yuichi Takamine

Koji Nosaka

Katsuya Daimon

Keiichi Umeda

Syunsuke Kido

Taku Kikuchi

Mari Saji

Takashi Miyake

Atsushi Tanaka

Tomio Kanazawa

An acoustic wave device includes an IDT electrode laminated on a piezoelectric substrate and defining a first resonator, and an IDT electrode laminated on the piezoelectric substrate and defining a second resonator. The first and second resonators are connected in parallel or in series. The IDT electrode of the first resonator includes an electrode layer including an epitaxial film and the IDT electrode of the second resonator includes an electrode layer including a non-epitaxial film.

Acoustic wave device and composite filter device

An acoustic wave device includes a silicon oxide film, a lithium tantalate film, an IDT electrode, and a protection film that are laminated on a support substrate made of silicon. A wavelength normalized film thickness of a lithium tantalate film is denoted by T, an Euler angle is θ, a wavelength normalized film thickness of the silicon oxide film is T, a wavelength normalized film thickness of the IDT electrode in terms of aluminum thickness is T, a wavelength normalized film thickness of a protection film is T, a propagation direction in the support substrate is ψ, and a wavelength normalized film thickness of the support substrate is T. Values of T, θ, T, T, T, and ψare set such that Icorresponding to an intensity of a response of a spurious response represented by Formula (1) is greater than about −2.4 in a spurious response.

Acoustic wave device, acoustic wave filter, and composite filter device

An acoustic wave device includes N band pass filters with first ends connected to define a common connection and having different pass bands. At least one of the band pass filters includes acoustic wave resonators including a lithium tantalate film having Euler angles (φ=0°±5°, θ, ψ=0°±15°), a silicon support substrate, a silicon oxide film between the lithium tantalate film and the silicon support substrate, an IDT electrode, and a protective film. In at least one acoustic wave resonator, a frequency fsatisfies Formula (3) or Formula (4) for all m where m>n:  Formula (3); and  Formula (4).In Formulas (3) and (4), fand frepresent the frequencies of the high-frequency end and the low-frequency end of the pass band in the m band pass filters.

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

An acoustic wave device is provided between a first terminal that is an antenna terminal and a second terminal that is different from the first terminal, and includes a plurality of acoustic wave resonators. The plurality of acoustic wave resonators include a plurality of series arm resonators and a plurality of parallel arm resonators. When the acoustic wave resonator electrically closest to the first terminal among the plurality of acoustic wave resonators is an antenna end resonator, the antenna end resonator is a SAW resonator or a BAW resonator. At least one acoustic wave resonator other than the antenna end resonator among the plurality of acoustic wave resonators is a first acoustic wave resonator.

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

An acoustic wave device includes a material layer which has Euler angles and an elastic constant at the Euler angles, a piezoelectric body which includes first and second principal surfaces opposing each other, is laminated directly or indirectly on the material layer so that the second principal surface is on the material layer side and has Euler angles, and whose elastic constant at the Euler angles, and an IDT electrode which is disposed on at least one of the first principal surface and the second principal surface of the piezoelectric body. At least one elastic constant among elastic constants Cto Cof the material layer not equal to 0 and at least one elastic constant among elastic constants Cto Cof the piezoelectric body not equal to 0 have opposite signs to each other.

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

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 &#x2212;2.4.

Acoustic wave device, multiplexer, radio-frequency front end circuit, and communication device

In an acoustic wave device, an antenna end resonator that is electrically closest to a first terminal is a first acoustic wave resonator. In each of the first acoustic wave resonator and a second acoustic wave resonator, a thickness of a piezoelectric layer is about 3.5&#x3bb; or less when a wavelength of an acoustic wave is denoted as &#x3bb;. The first acoustic wave resonator and the second acoustic wave resonator satisfy at least one of a first condition, a second condition, and a third condition. The first condition is a condition that the first acoustic wave resonator further includes a dielectric film provided between the piezoelectric layer and an interdigital transducer electrode, and the second acoustic wave resonator does not include the dielectric film.

An acoustic wave device includes a material layer with Euler angles and an elastic constant at the Euler angles represented by Expression 1, a piezoelectric body including opposing first and second principal surfaces, is laminated directly or indirectly on the material layer and has Euler angles, and whose elastic constant at the Euler angles is represented by the Expression 1 below, and an IDT electrode on at least one of first and second principal surfaces of the piezoelectric body, and in which a wave length determined by an electrode finger pitch is &#x3bb;. A product of Cand Chas a positive value, and an absolute value of Cof the material layer is greater than an absolute value of Cof the piezoelectric body 

In a multiplexer, at least one acoustic wave filter includes a piezoelectric body made of lithium tantalate having Euler angles (&#x3c6;=0&#xb0;&#xb1;5&#xb0;, &#x3b8;, &#x3c8;=0&#xb0;&#xb1;15&#xb0;), a support substrate, and an interdigital transducer (IDT) electrode. A frequency fof a first higher-order mode satisfies below Formulas (3) and (4) in all acoustic wave filters (m) having a higher pass band than at least one acoustic wave filter (n) (n&#x3c;m&#x2264;N) in at least one acoustic wave resonator among a plurality of acoustic wave resonators. f&#x3e;fFormula (3). f&#x3c;fFormula (4). Here, fand frepresent the frequencies of the high-frequency end and the low-frequency end of the pass band in the m acoustic wave filters in Formulas (3) and (4).

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

A multiplexer includes N acoustic wave filters each including one end connected in common and having a different pass band, in which when the N acoustic wave filters are in order from a side of a lower frequency of the pass band, at least one n-th acoustic wave filter among the N acoustic wave filters excluding an acoustic wave filter having the highest frequency of the pass band includes one or more acoustic wave resonators including a support substrate, a silicon nitride film laminated on the support substrate, a silicon oxide film laminated on the silicon nitride film, a piezoelectric body laminated on the silicon oxide film, and an IDT electrode provided on the piezoelectric body. All acoustic wave filters having a pass band in a higher frequency than a frequency of a pass band of the n-th acoustic wave filter satisfy f&#x3e;for f&#x3c;f.

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

An elastic wave device includes a piezoelectric layer, an IDT electrode on the piezoelectric layer, a high-acoustic-velocity member, a low-acoustic-velocity film between the high-acoustic-velocity member and the piezoelectric layer. The piezoelectric layer is made of lithium tantalate, the IDT electrode includes metal layers including an Al metal layer and a metal layer having a higher density than Al. Expression 1 is satisfied: 301.74667&#x2212;10.83029&#xd7;T&#x2212;3.52155&#xd7;T+0.10788&#xd7;T+0.01003&#xd7;T+0.03989&#xd7;T&#xd7;T&#x2265;0 expression 1, where &#x3bb; represents a wavelength defined by an electrode finger pitch of the IDT electrode, T(%) represents a normalized film thickness of the piezoelectric layer to the wavelength &#x3bb;, and T(%) represents a normalized film thickness of the IDT electrode in terms of Al to the wavelength &#x3bb;.

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

An acoustic wave device includes an interdigital transducer electrode provided on a piezoelectric substrate, the interdigital transducer electrode includes first and second electrode fingers. The second electrode fingers are connected to an electric potential different from that of the first electrode fingers. A direction orthogonal or substantially orthogonal to a direction in which the first electrode fingers and the second electrode fingers extend is an acoustic wave propagation direction, the interdigital transducer electrode includes a first area centrally provided in the acoustic wave propagation direction, second areas provided on one side and another side of the first area in the acoustic wave propagation direction, and third areas each provided on a side of each of the second areas opposite to the first area in the acoustic wave propagation direction.

Acoustic wave device, filter, and composite filter device

In an acoustic wave device, an antenna end resonator electrically closest to a first terminal is a first acoustic wave resonator. In each of the first acoustic wave resonator and a second acoustic wave resonator, a thickness of a piezoelectric layer is equal to or less than about 3.5&#x3bb;. A cut angle of the piezoelectric layer of the first acoustic wave resonator is within a range of &#x3b8;&#xb1;4&#xb0;. The cut angle of the piezoelectric layer of the second acoustic wave resonator has a larger difference from &#x3b8;(&#xb0;) than the cut angle of the piezoelectric layer of the first acoustic wave resonator.

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

An acoustic wave device includes a piezoelectric substrate including an electrode formation surface, and an IDT electrode provided on the electrode formation surface. The IDT electrode includes a close contact layer located on the electrode formation surface, and a main electrode layer located on the close contact layer. The close contact layer includes first and second layers that respectively include first and second lateral surfaces. An area of a surface of the second layer that is in close contact with the main electrode layer is smaller than an area of a surface of the first layer that is in close contact with the piezoelectric substrate. An inclination angle of the second lateral surface is smaller than an inclination angle of the first lateral surface.

Acoustic wave device and manufacturing method for same

An acoustic wave device includes a silicon oxide film, a piezoelectric body made of lithium tantalate, and interdigital transducer electrodes stacked on a supporting substrate made of silicon, in which the values of the wave length-normalized film thickness and the Euler angle of the piezoelectric body made of lithium tantalate, the wave length-normalized film thickness of the silicon oxide film, the wave length-normalized film thickness of the interdigital transducer electrodes in terms of aluminum thickness, the propagation direction of the supporting substrate, and the wave length-normalized film thickness of the supporting substrate are set such that represented by Formula (1) for at least one of responses of first, second, and third higher-order modes is more than about &#x2212;2.4, and T&#x3e;20.

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Nagaokakyo, Japan

Ryo Nakagawa