Murata Manufacturing Co., Ltd.

Daisuke Yamamoto

Hajime Kando

Michio Kadota

Nobuhira Tanaka

Takeshi Nakao

Toshiyuki Fuyutsume

Masahiko Saeki

Shunsuke Kido

Akihiro Teramoto

In a boundary acoustic wave resonator, apodization weighting is performed on an IDT electrode so that an intersecting width decreases as a location moves outward in a boundary acoustic wave propagation direction. An inner side of a first busbar includes inclined portions that are disposed a predetermined distance from an envelope portion Bon the side of the first busbar. An inner side of a second busbar includes inclined portions that are disposed a predetermined distance from an envelope portion on the side of second busbar. The sum of the numbers of electrode fingers and dummy electrodes that a straight line extending from the end of at least one of electrode fingers in the boundary acoustic wave propagation direction crosses before reaching the side of the first busbar or the side of the second busbar is equal to or greater than 5.

Boundary acoustic wave resonator and ladder filter

An acoustic wave element includes an IDT electrode in contact with a piezoelectric material and including a plurality of electrode fingers, which include first and second electrode fingers that adjoin each other in an acoustic wave propagation direction and that connect to different potentials and a first dummy electrode finger facing the first electrode finger via a gap located on an outer side in an electrode finger length direction of the first electrode finger. At an area near the gap, first protrusions are provided in at least one of the first electrode finger and the first dummy electrode finger, the first protrusion protruding in the acoustic wave propagation direction from at least one of side edges of the at least one of the first electrode finger and the first dummy electrode finger. The acoustic wave element has greatly improved resonance characteristics of a resonance frequency and prevents short-circuit failure between electrode fingers and degradation in insulation properties.

Acoustic wave element having an electrode finger with a protrusion

A boundary acoustic wave device includes a first medium, a second medium, and an IDT electrode disposed at an interface between the first medium and the second medium, the IDT electrode having an Au layer defining a main electrode layer, wherein a Ni layer is laminated so as to contact at least one surface of the Au layer, and a portion of Ni defining the Ni layer is diffused from the Ni layer side surface of the Au layer toward the inside of the Au layer.

Boundary acoustic wave device comprising Ni diffused in Au and method for manufacturing the same

A surface acoustic wave device includes a LiNbOsubstrate with a Euler angle in an area defined by a rectangle having four corners with coordinates (1) (0&#xb0;, 7&#xb0;, 101&#xb0;), (2) (0&#xb0;, 23&#xb0;, 79&#xb0;), (3) (0&#xb0;, 23&#xb0;, 79&#xb0;), and (4) (0&#xb0;, 7&#xb0;, 79&#xb0;), for example, and an electrode film made of Au, wherein surface acoustic waves including a longitudinal wave component as a main component are propagated thereon. The surface acoustic wave device uses longitudinal surface acoustic waves having a phase speed greater than with the 'slow transverse wave', and has a great electromechanical coupling coefficient and small propagation loss, and is suitable for handling high-frequency signals.

Surface acoustic wave device

A surface acoustic wave device includes a LiNbOsubstrate with a Euler angle in an area defined by a rectangle having four comers with coordinates () (0&#xb0;, 7&#xb0;, 101&#xb0;), () (0&#xb0;, 23&#xb0;, 79&#xb0;), () (0&#xb0;, 23&#xb0;, 79&#xb0;), and () (0&#xb0;, 7&#xb0;, 79&#xb0;), for example, and an electrode film made of Au, wherein surface acoustic waves including a longitudinal wave component as a main component are propagated thereon. The surface acoustic wave device uses longitudinal surface acoustic waves having a phase speed greater than with the 'slow transverse wave', and has a great electromechanical coupling coefficient and small propagation loss, and is suitable for handling high-frequency signals.

Growing community of inventors

Muko, Japan

Daisuke Yamamoto