| 摘要 |
PROBLEM TO BE SOLVED: To obtain comb-line electrode structure to eliminate the creeping electric field from the tip of a crossing part of a comb-line electrode and to surely secure capacity for the length of a desired cross finger irrespective of an error of crossing length of the comb-line electrode of a transversal type surface acoustic wave filter. SOLUTION: An intermediate bus bar 5 is arranged between bus bars 3, 4 which are relatively arranged in parallel and a first and a second comb-line electrodes 6, 7 are constituted by each bus bar and the intermediate bus bar by the surface acoustic wave filter. In this case, regarding a phase observed at the crossing part of the surface acoustic wave filter constituted of the first comb-line electrode 6, the phase which is completely opposite of the one observed at the crossing part of the second comb-line electrode 7 is obtained. Therefore, the crossing length of the cross finger of the first comb-line electrode 6 is defined as (a)+(b), the crossing length of the cross finger of the second comb-line electrode 7 is defined as b for the length by (a)+(b)+δactually includingδas a length component of intensity of the electric field in appearance and the crossing length (a) of the cross finger which is difference of the capacity of the length (b)+δactually includingδas the length component of the intensity of the electric field in appearance is obtained.
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