Kyocera Corporation

Soichiro Nozoe

Tetsuya Kishino

Motoki Ito

Naofumi Kasamatsu

A cavity overlapping an IDT electrode in a see-through plan view is formed between a piezoelectric layer and a support. An intersection region where first electrode fingers and second electrode fingers overlap each other includes a central region and two end regions located on both sides of the central region in one-to-one correspondence. The cavity overlaps the central region. An edge of the cavity on a side closer to the first busbar is located within a range from an edge of the central region on a side closer to the first busbar to an edge of the first busbar on a side opposite to the central region. The first electrode fingers extending from the first busbar each include a first portion located in the central region and a second portion located on a side closer to the first busbar or a side closer to the second busbar relative to the central region. A value of mass per unit length of the first electrode fingers above lower surfaces thereof is greater in the second portions than in the first portions.

Elastic wave element and communication device

The strength of a spurious signal is reduced while maintaining the uniformity of a resonant frequency in an identical elastic wave resonator. An elastic wave resonator () includes a piezoelectric body (), and a plurality of electrode fingers () located on the piezoelectric body and arranged in a propagation direction (TD) of an elastic wave. A region in which the plurality of electrode fingers are located includes a first region (A) and a second region (B) in a plan view. The plurality of electrode fingers include a first electrode finger group (A) located in the first region and a second electrode finger group (B) located in the second region, and a pitch (PA) of the first electrode finger group is different from a pitch (PB) of the second electrode finger group. The first region and the second region have frequency effective-characteristics acting in a direction to cancel out effects on a higher resonant or antiresonant frequency and a lower resonant or antiresonant frequency brought about by a magnitude correlation between the pitches of the first and second electrode finger groups.

Elastic wave resonator, elastic wave filter, demultiplexer, and communication apparatus

An elastic wave device includes a substrate, a multilayer film located on the substrate, a piezoelectric layer located on the multilayer film, and an IDT electrode located on the piezoelectric layer. The IDT electrode includes electrode fingers each having a large width from a portion connected to a busbar to a position overlapping tip ends of the other electrode fingers when viewed in an arrangement direction of the electrode fingers.

Elastic wave device, splitter, and communication apparatus

An acoustic wave element includes an IDT electrode including a plurality of electrode fingers and exciting a surface acoustic wave, a first substrate including an upper surface on which the IDT electrode is located, the first substrate being configured by a piezoelectric crystal, and a second substrate bonded to a side where a lower surface of the first substrate is located. Either of a first region which continues from the lower surface of the first substrate toward a side where the upper surface is located or a second region which continues from the lower surface of the first substrate toward a side where the second substrate is located is a low resistance region having a resistance value of 5&#xd7;10&#x3a9; to 5&#xd7;10&#x3a9;.

Acoustic wave element

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.

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Kyoto, Japan

Soichiro Nozoe