| 摘要 |
A ferroelectric surface wave transducer device comprising an unpoled ferroelectric substrate having a substantially sinusoidal poled region at a surface thereof. A metal plate electrode is disposed on the opposing surface of the substrate. In operation an A.C. voltage applied across the two electrodes gives rise to a surface elastic wave in the substrate. Also disclosed is a method of producing a surface wave transducer of the type described. A pair of interdigitated metal electrodes are applied to a surface of an unpoled ferroelectric substrate. A poling potential is applied between the electrodes, preferably while the substrate is heated. The interdigitated electrodes are then removed and a metal plate electrode is applied over the region where the interdigitated electrodes had been. Finally, another metal electrode is applied to the opposite surface of the substrate. In a preferred embodiment of the invention the interdigitated electrodes are in the form of a moveable fixture. The fixture is moved into contact with an unpoled substrate of ferroelectric material and, after the poling potential is applied, it is moved out of contact with the substrate. In this manner the fixture can be used repeatedly to selectively pole ferroelectric substrates upon which simple plate electrodes are then applied.
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