Kyocera Corporation

Motoki Ito

Tetsuya Kishino

Kiyohiro Iioka

Yuuko Yokota

Shigehiko Nagamine

Tsuyoshi Nakai

Yoshifumi Yamagata

Wataru Koga

Masayuki Funami

Takanori Ikuta

Kazuhiro Otsuka

Daisuke Makibuchi

Tomonori Urata

Kouichi Maruta

Soichiro Nozoe

Tomofumi Nakamura

Naoki Hashimura

An acoustic wave device includes a substrate, a multilayer film on the substrate, an LT layer which is located on the multilayer film and is configured by a single crystal of LiTaO, and an IDT electrode on the LT layer. In the multilayer film, a differential value obtained by subtracting a total value of values each obtained by multiplying a density and thickness of a film having a slower acoustic velocity than a transverse wave acoustic velocity of the LT layer from a total value of values each obtained by multiplying a density and thickness of a film having a faster acoustic velocity than the transverse wave acoustic velocity of the LT layer is negative, and a thickness of the LT layer is less than p and a thickness of the multilayer film is less than p where a pitch of electrode fingers in the IDT electrode is 'p'.

Acoustic wave device, multiplexer, and communication apparatus

An acoustic wave element includes an IDT electrode including electrode fingers, a first substrate on an upper surface of which the IDT electrode is located, which has a thickness of less than 2 times a repetition interval of the electrode fingers and is configured by a piezoelectric crystal, a second substrate bonded to a lower surface of the first substrate, and configured by an Si single crystal having a plane orientation of a (100) plane or (110) plane or a plane equal to them, in which substrate a crystal axis of the Si single crystal parallel to a substrate surface of Si single crystal is inclined at any angle of 25&#xb0; to 65&#xb0;, 115&#xb0; to 155&#xb0;, 205&#xb0; to 245&#xb0;, and 295&#xb0; to 345&#xb0; relative to a direction of propagation of an acoustic wave when viewed from the upper surface of the superposed first substrate.

Acoustic wave element

A SAW device includes a mounting substrate including a mounting surface, a SAW chip mounted on the mounting surface, a dummy chip mounted on the mounting surface, and a resin part covering the acoustic wave chip and the dummy chip. The dummy chip includes an insulating dummy substrate, and one or more dummy terminals which are located on a surface of the dummy substrate on the mounting surface side and are bonded to the mounting surface. The dummy chip configures an open end when electrically viewed from the mounting substrate side.

Acoustic wave device and communication apparatus

An acoustic wave device includes a substrate, a multilayer film on the substrate, an LT layer configured by a single crystal of LiTaOon the multilayer film, and an IDT electrode on the LT layer. The thickness of the LT layer is 0.3&#x3bb; or less where &#x3bb; is two times a pitch p of electrode fingers in the IDT electrode. Euler angles of the LT layer are (0&#xb0;&#xb1;20&#xb0;, &#x2212;5&#xb0; to 65&#xb0;, 0&#xb0;&#xb1;10&#xb0;), (&#x2212;120&#xb0;&#xb1;20&#xb0;, &#x2212;5&#xb0; to 65&#xb0;, 0&#xb0;&#xb1;10&#xb0;), or (120&#xb0;&#xb1;20&#xb0;, &#x2212;5&#xb0; to 65&#xb0;, 0&#xb0;&#xb1;10&#xb0;). The multilayer film configured by alternately stacking at least one first layer and at least one second layer. The first layer is comprised of SiO. The second layer is comprised of any one of TaO, HfO, ZrO, TiO, and MgO.

An acoustic wave device includes a substrate, a multilayer filmon the substrate, an LT layerwhich is located on the multilayer film and is configured by a single crystal of LiTaO, and an IDT electrodeon the LT layer. In the multilayer film, a differential value D obtained by subtracting a total value of values each obtained by multiplying a density and thickness of a film having a slower acoustic velocity than a transverse wave acoustic velocity of the LT layerfrom a total value of values each obtained by multiplying a density and thickness of a film having a faster acoustic velocity than the transverse wave acoustic velocity of the LT layeris negative, and a thickness of the LT layeris less than 2p where a pitch of electrode fingers in the IDT electrodeis 'p'.

A filter body includes a serial arm and one or more parallel resonators in a state where they are connected in a ladder shape. The serial arm includes a plurality of serial resonators connected in series to each other. A difference of resonance frequencies among the plurality of serial resonators is smaller than a half of a difference between the resonance frequency and an antiresonance frequency of each serial resonator. The serial arm includes a first divided arm which extends from one side toward the other side in a predetermined direction on the piezoelectric substrate, and a second divided arm which is folded back from the other side of the first divided arm and extends toward the one side. The shield conductor includes a portion which is located between at least one of the serial resonators included in the first divided arm and at least one of the serial resonators included in the second divided arm.

Acoustic wave filter, multiplexer, and communication apparatus

A SAW filter includes a piezoelectric substrate, a serial arm and a parallel resonance portion. The serial arm includes one or more serial resonance portions. The parallel resonance portion is located on the piezoelectric substrate and configures a ladder-type filter together with the serial arm. The parallel resonance portion includes a parallel resonator and a capacity element. The parallel resonator includes an IDT electrodes on the piezoelectric substrate and a pair of reflectors on the two sides thereof. The capacity element is connected in parallel with the parallel resonator. A capacitance of the capacity element is 0.8 time or more of a capacitance of the IDT electrode in the parallel resonator. A difference between an anti-resonance frequency and a resonance frequency of the first parallel resonance portion is smaller than a difference between an anti-resonance frequency and a resonance frequency of the first parallel resonator.

Acoustic wave filter, acoustic wave device, multiplexer, and communication apparatus

An acoustic wave device includes a plurality of serial resonators and a plurality of parallel resonators configured by acoustic wave elements, which plurality of serial resonators and plurality of parallel resonators configure a filter in which they are connected in a ladder configuration; a first capacitance part which is connected in parallel to at least one of the plurality of serial resonators; and a second capacitance part which is connected in series to at least one of the plurality of parallel resonators.

An SAW resonator includes a piezoelectric substrate, an IDT electrode, and a pair of reflectors. The IDT electrode includes pluralities of electrode fingers which are aligned on the piezoelectric substrate in a direction of propagation of a SAW. The pair of reflectors are located on the two sides of the pluralities of electrode fingers on the piezoelectric substrate in the direction of propagation. The IDT electrode includes a plurality of areas which includes pluralities of electrode fingers distributed to them and have different resonance frequencies from each other. The plurality of areas include at least three areas. The second highest resonance frequency among all areas is lower than an intermediate value between the lowest resonance frequency among all areas and the highest resonance frequency among all areas.

Acoustic wave resonator, acoustic wave filter, multiplexer, and communication apparatus

An input port, an output port, and a plurality of serial resonators and a plurality of parallel resonators connected in a ladder type between the input port and the output port and including IDT electrodes are provided. The plurality of parallel resonators include at least one first parallel resonator having a resonance frequency lower than resonance frequencies of the plurality of serial resonators, and at least one second parallel resonator having a resonance frequency higher than antiresonance frequencies of the plurality of serial resonators.

Filter, multiplexer, and communication apparatus

An acoustic wave filter has a first signal line connecting one among the plurality of first IDT electrodes and the first balanced signal terminal; a second signal line connecting the other first IDT electrode with the second balanced signal terminal; a third signal line connecting one among the plurality of second IDT electrodes with the second balanced signal terminal; and a fourth signal line connecting the other second IDT electrode with the first balanced signal terminal. The fourth signal line has an intersection portion three-dimensionally intersecting with a part of the second signal line. The intersection portion extends in a direction inclined relative to the second signal line on the major surface.

Acoustic wave filter

The present invention provides a duplexer using a ladder-type filter, which has a small size and is superior in isolation characteristic, and a communication apparatus using such a duplexer. A series resonator (R) contained in a first filter element (F) and a parallel resonator (R) contained in a second filter element (F) are disposed so as not to allow the elastic wave propagating paths to be overlapped with each other. By disposing them in this manner, it is possible to prevent an elastic wave, leaked from the series resonator (R) and most influential to the isolation characteristic, from being received by the parallel resonator (R). Consequently, it is possible to achieve a small-size duplexer that is superior in isolation characteristic.

Duplexer and communication apparatus using the same

A SAW device Daccording to the present invention comprises a ladder-type SAW device Tfor transmission and a ladder-type SAW device Rfor receiving on a main surface of a piezoelectric substrate. The ratio (LT/PT) of the width LT of electrode fingers to the pitch PT between the electrode fingers in a SAW resonator Sin the ladder-type SAW device Tfor transmission is made lower than the ratio (LR/PR) of the width LR of electrode fingers to the pitch PR between the electrode fingers in a SAW resonator Sin the ladder-type SAW device Rfor receiving. As a result, the SAW device Dhas a low loss within a band and has steep attenuation characteristics outside the band, and is miniaturized.

Surface acoustic wave device, duplexer, and communications equipment

After electrode patterning on an electrode forming surface of a piezoelectric substrate(FIG.()), a conductor layer is formed on an electrode non-forming surface of the piezoelectric substrate(FIG.()). After forming the conductor layer, the conductor layer formed on the other surface is removed (FIG.()) after at least one step (FIG.()), and thereafter, dicing for separation into elements and mounting on a mounting substrate are carried out. By removing all the conductor layer on the other surface of the piezoelectric substrate, the out-of-passband attenuation and isolation performance can be significantly improved.

Surface acoustic wave device manufacturing method, surface acoustic wave device, and communications equipment

An IDT electrode, and an input electrode sectionand an output electrode sectioneach connecting with the IDT electrodeare formed in a filter region on one main surface of a piezoelectric substrate, and a semiconductor layeris formed on the other main surface opposite to the one main surface of the piezoelectric substrate. The semiconductor layermakes it possible to prevent pyroelectric destruction in the device manufacturing process as well as to prevent out-of-band attenuation characteristics from being degraded.

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Kyoto, Japan

Motoki Ito