| 摘要 |
PURPOSE:To reduce a reflected wave of a surface acoustic wave (SAW) by a metal edge effect without raising an accuracy of working by joining a dummy electrode finger with an adjacent driving electrode finger, and forming them as one body. CONSTITUTION:A driving electrode finger part 5 of lambda/4 width and one dummy electrode finger part 4 of lambda/4 width which is adjacent to said electrode finger part are joined and formed as one body, and constitute an electrode finger, and also each electrode finger is placed so that an interval of the diving electrode finger part of the adjacent electrode finger becomes lambda/4. According to this constitution, a reflected wave by a metal of an SAW becomes as shown in a figure (a), a phase relation of the reflected wave in A of the figure becomes as a figure (b), and each reflected wave of (1), (2) and (3) becomes an opposite phase to each other and synthesized in the negating direction. Accordingly, the reflected wave generated by the driving electrode can be negated by the reflected wavey generated by the dummy electrode, by using a width and an interval of the electrode finger of the minimum 1/4lambda. |
