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US 2011/0227668 A1Published application
Surface Acoustic Wave Filter and Duplexer
AssigneeKYOCERA Corporation
InventorHiroyuki Tanaka
Life of this patent
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Abstract
A surface acoustic wave filter and a duplexer are provided. In a surface acoustic wave filter, on a piezoelectric substrate, a first IDT electrode composed of an input/output electrode and a first floating electrode, and a second IDT electrode composed of a ground electrode and a second floating electrode are arranged, and are connected in series to each other via the first floating electrode and the second floating electrode to form IDTs. In two serial IDTs arranged next to each other, an electrode finger of the input/output electrode in the first IDT electrode of the one serial IDT is arranged next to an electrode finger of the ground electrode in the second IDT electrode of the other serial IDT.
Claims9
A surface acoustic wave filter, comprising:
- a plurality of series-connected type I DT electrodes each comprising
- a first IDT electrode which comprises an input/output electrode comprising a plurality of first electrode fingers, and a first floating electrode with a floating state electrically comprising a plurality of second electrode fingers, and
- a second IDT electrode which comprises a ground electrode comprising a plurality of third electrode fingers, and a second floating electrode with a floating state electrically comprising a plurality of fourth electrode fingers and being connected to the first floating electrode, wherein
- the plurality of series-connected type IDT electrodes comprises a first series-connected type IDT electrode and a second series-connected type IDT electrode which is adjacent to the first series-connected type IDT electrode, the first IDT electrode of the first series-connected type IDT electrode and the second IDT electrode of the second series-connected type IDT electrode being located next to each other,
- at least one of the plurality of first electrode fingers of the first series-connected type IDT electrode is located facing the second series-connected type IDT electrode, and
- at least one of the plurality of third electrode fingers of the first series-connected type IDT electrode is located facing the second series-connected type IDT electrode,
- at least one of the plurality of first electrode fingers of the second series-connected type IDT electrode is located facing the first series-connected type IDT electrode, and at least one of the plurality of third electrode fingers of the second series-connected type IDT electrode is located facing the first series-connected type IDT electrode.
4 more elements
A surface acoustic wave filter, comprising:
- a plurality of series-connected type IDT electrodes each comprising
- a first IDT electrode which comprises an input/output electrode comprising a plurality of first electrode fingers, and a first floating electrode with a floating state electrically comprising a plurality of second electrode fingers, and
- a second IDT electrode which comprises a ground electrode comprising a plurality of third electrode fingers, and a second floating electrode with a floating state electrically comprising a plurality of fourth electrode fingers and being connected to the first floating electrode;
- a first common electrode connected to each of the plurality of first electrode fingers;
- a second common electrode connected to each of the plurality of second electrode fingers;
- a third common electrode connected to each of the plurality of third electrode fingers;
- and
- a fourth common electrode connected to each of the plurality of fourth electrode fingers, wherein
- the plurality of series-connected type IDT electrodes comprises a first series-connected type IDT electrode and a second series-connected type IDT electrode which is adjacent to the first series-connected type IDT electrode, the first IDT electrode of the first series-connected type IDT electrode and the second IDT electrode of the second series-connected type IDT electrode being located next to each other,
- at least one of the plurality of first electrode fingers of the first series-connected type IDT electrode is located facing the second series-connected type IDT electrode,
- at least one of the plurality of third electrode fingers of the second series-connected type IDT, electrode is located facing the first series-connected type IDT electrode, and
- out of the plurality of third electrode fingers of the second series-connected type IDT electrode, the electrode finger located facing the first series-connected type IDT electrode being located between the second common electrode of the first series-connected type IDT electrode and the fourth common electrode of the second series-connected type IDT electrode.
9 more elements
A surface acoustic wave filter, comprising:
- a plurality of series-connected type IDT electrodes each comprising
- a first IDT electrode which comprises an input/output electrode comprising a plurality of first electrode fingers, and a first floating electrode with a floating state electrically comprising a plurality of second electrode fingers, and
- a second IDT electrode which comprises a ground electrode comprising a plurality of third electrode fingers, and a second floating electrode with a floating state electrically comprising a plurality of fourth electrode fingers and being connected to the first floating electrode;
- and
- reflectors being located both sides of an array of the plurality of series-connected type IDT electrodes which are arranged next to each other, in a direction along a propagation direction of a surface acoustic wave so as to interpose the array of the plurality of series-connected type IDT electrodes therebetween, wherein
- the plurality of series-connected type IDT electrodes comprises a first series-connected type IDT electrode and a second series-connected type IDT electrode which is adjacent to the first series-connected type IDT electrode, the first DT electrode of the first series-connected type IDT electrode and the second IDT electrode of the second series-connected type IDT electrode being located next to each other,
- at least one of the plurality of first electrode fingers of the first series-connected type IDT electrode is located facing the second series-connected type IDT electrode,
- at least one of the plurality of third electrode fingers of the second series-connected type IDT electrode is located facing the first series-connected type IDT electrode.
5 more elements
Dependencies are inferred from the claim text.