SURFACE ACOUSTIC WAVE ELEMENT

摘要

PROBLEM TO BE SOLVED: To obtain an element by which a designing work and a confirming work of electrode fingers are conveniently performed without degrading frequency characteristics by forming plural reflecting means which are formed like a belt on a piezoelectric substrate and forming width of the reflecting means with the stepwise preset width for every plural reflecting means when surface acoustic waves to be transmitted on the piezoelectric substrate are reflected. SOLUTION: A reflector 105 is provided on the side to be opposed to an interdigital type transducer 102 on the input side in the direction of an arrow X1, namely, in the direction of an arrow Y1 of a coupler 104 and reflects prescribed surface acoustic waves. The reflector 105 is constituted of plural electrode fingers 120 whose width is stepwise different and which are opened one another. A reflector 106 is provided on the side to be opposed to an inter digital type transducer 103 on the output side on the side of the arrow X1 of the coupler 104, namely, on the side in the direction of the arrow Y2 and reflects the prescribed surface acoustic waves. The reflector 106 is constituted of plural electrode fingers 121 that width of grading is stepwise different and which are opened each other.