SURFACE ACOUSTIC WAVE FILTER

摘要

PROBLEM TO BE SOLVED: To provide a surface acoustic wave filter realizing a steep shift band without narrowing the width of a pass band. SOLUTION: In positive electrode fingers 23 which one comb-line electrode 21 installed in an input comb-line electrode 20 has and negative electrode fingers 26 that the other comb-line electrode 24 has, the lengths of the positive electrode fingers 23 and the negative electrode fingers 26, which exist in end parts 28 and 29 in the arranging direction of the positive electrode fingers 23 and the negative electrode fingers 26, are made to be shorter than those of the positive electrode fingers 23 and the negative electrode fingers 26, which exist in the center part 27 of the arranging direction.