| 摘要 |
A transducer for surface acoustic waves, and a resonator and a filter for surface acoustic waves having the transducer are provided. The transducer for surface acoustic waves has cells containing two electrode fingers per cell, wherein the transducer exhibits unidirectional behavior for propagation directions of the surface acoustic waves parallel to highly symmetrical directions of the crystal substrate. Each of two electrodes have a plurality of electrode fingers, the electrode fingers having center axes extending parallel to their longitudinal axes and being spaced apart from center axes of adjacent electrode fingers of the same electrode by a distance which equals the ratio of the velocity of the surface acoustic wave and the cut-off frequency of the transducer. The electrode fingers of both electrodes define a plurality of cells each consisting of two fingers.
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