SURFACE ACOUSTIC WAVE ELEMENT

摘要

PROBLEM TO BE SOLVED: To construct a transmitting surface acoustic wave filter of a small loss. SOLUTION: Each electrode is formed along the propagation direction of a surface acoustic wave in the following manner. When the wavelength of a surface acoustic waveλ, the width of a positive electric finger is set to be aboutλ/8, a distance d1 from the center of the positive electric finger to the center of a first negative electric finger whose electrode W1 is within the range of 18/80λ<=W1 <=20/80λbecomes 23/80λ<=d1 <=25/80λ, and furthermore, a distance d2 between a second negative electric finger whose electrode width W2 is within the range of 20/80λ<=W2 <=26/80λand the center of the positive electric finger becomes 54/80λ<=d2 <=55/80λ.