| 摘要 |
PURPOSE:To make small in size of a piezoelectric substance and to make low the cost of a surface acoustic wave filter, by folding a multistrip coupler MSC. CONSTITUTION:An input transducer 10, multistrip coupler (MSC)12 and output transducer 11 are located on a piezoelectric substrate 9. The MSC12 is composed of a plurality of strips of parallel electrodes, and it is folded at the center lengthwise the electrodes and the upper and lower part is made vertical toward the lengthwise direction of the electrodes and the input transducer 10 and the output transducer 11 are moved in parallel so that they are closed with each other. Thus, the length of the piezoelectric substrate 9 can be reduced by the length of parallel movement of the MSC. |
