Acoustic wave element and communication apparatus
AssigneeKYOCERA Corporation
InventorsMasaya Kawaguchi, Tetsuya Kishino
Life of this patent
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Abstract
In an IDT electrode of an acoustic wave element which includes first electrode fingers and second electrode fingers connected to potentials which are different from each other and arranged spaced apart from each other, the first electrode fingers includes first tip parts, and either of the first electrode fingers and the second electrode fingers includes, at a tip area extending along a direction of propagation of an acoustic wave and overlapping with the first tip parts, increase sections in which electrode volumes per unit lengths in a direction of extension of the first electrode fingers and the second electrode fingers are larger in comparison with that of the center area in which the electrode fingers intersect.
Claims12
An acoustic wave element comprising:
- a piezoelectric substrate;
- and
- an IDT electrode on an upper surface of the piezoelectric substrate,
- wherein the IDT electrode comprises
- a first bus bar and second bus bar which are connected to potentials different from each other and are located spaced apart from each other,
- first electrode fingers, connected to the first bus bar and extending to the second bus bar side, and
- second electrode fingers, connected to the second bus bar and extending to the first bus bar side, located so as to be adjacent to each other along a direction of propagation of an acoustic wave,
- second dummy electrodes which are connected to the second bus bar and face the first electrode fingers across first gaps, and
- first dummy electrodes which are connected to the first bus bar and face the second electrode fingers across second gaps,
- three areas extending along the direction of propagation of the acoustic wave comprised of a center area comprising a portion in which the first electrode fingers and the second electrode fingers intersect and areas on the two sides of the center area comprised of a first end area closer to the first bus bar side than the center area and a second end area closer to the second bus bar side than the center area,
- the first electrode fingers comprises first tip parts in the second end area, and
- either of the first electrode fingers and the second electrode fingers comprises, at a tip area extending along the direction of propagation of the acoustic wave and overlapping with the first tip parts, increase sections which have a larger electrode volume per unit length in a direction of extension of the first electrode fingers and second electrode fingers in comparison with that of the center area, wherein, in the direction of propagation of the acoustic wave, the increase sections within the tip area are only located on alternating portions of the first electrode fingers and the second electrode fingers within the tip area.
Dependencies are inferred from the claim text.