| 摘要 |
PROBLEM TO BE SOLVED: To provide a high balancing 5IDT longitudinal joined resonator type acoustic surface wave device having balanced unbalance transducer function. SOLUTION: The longitudinal joined resonator type acoustic surface wave filter device having the IDT type balanced unbalance transducer function has a first and second segmented electrodes 110, 111 which are formed by splitting of a centrally-placed inter-digital transducer in acoustic surface wave propagation direction. The first and second segmented electrodes 110, 111 are connected to first and second balanced terminals 108, 109. One inter-digital transducer out of two inter-digital transducers placed at both sides of the centrally-placed inter-digital transducer is inversed to the other inter-digital transducer. The two inter-digital transducers on both sides of the centrally-placed inter-digital transducer are connected to a unbalance signal terminal 107. Each tight pitch electrode digit is provided for the gap side end of one inter-digital transducer and the gap side end of another inter-digital transducer being adjacent to each other in surface wave propagation direction. COPYRIGHT: (C)2005,JPO&NCIPI
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