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US 2004/0000839 A1Published application
Surface acoustic wave device and communication device
AssigneeMurata Manufacturing Co., Ltd.
InventorsOsamu Shibata, Yoichi Sawada
Life of this patent
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Abstract
A surface acoustic wave device includes at least four surface acoustic wave elements that are arranged to have an unbalanced-to-balanced conversion function. In a surface acoustic wave element on the balanced side, the phase between the input and output terminals is 180 degrees shifted so that the phase difference between the outputs on the balanced side becomes substantially 180 degrees.
Claims23
A surface acoustic wave device comprising:
- a piezoelectric substrate;
- input and output terminals;
- and
- at least four surface acoustic wave elements, each of which has a plurality of comb-shaped electrode portions arranged along a propagation direction of a surface acoustic wave and reflectors disposed outside the comb-shaped electrode portions, on said piezoelectric substrate;
- wherein an unbalanced-to-balanced conversion function is included and wherein, in order to make the phase difference of the outputs on the balanced side substantially 180 degrees, one of the at least four surface acoustic wave elements in which the phase is 180 degrees shifted between the input and output terminals, is disposed on the balanced side.
2 more elements
A surface acoustic wave device comprising:
- a piezoelectric substrate;
- input and output terminals;
- and
- a plurality of surface acoustic wave elements, each of which has a plurality of comb-shaped electrode portions arranged along a propagation direction of a surface acoustic wave on said piezoelectric substrate;
- wherein an unbalanced-to-balanced conversion function is included and wherein, in order to make the phase difference of the outputs on the balanced side substantially 180 degrees, one of the plurality of surface acoustic wave elements in which the phase is 180 degrees shifted between the input and output terminals, is disposed on the balanced side.
2 more elements
Dependencies are inferred from the claim text.