| 摘要 |
PURPOSE:To realize the inductive impedance for the central roller screen type electrode, by setting reed screen type electrodes connected to each other at both sides of a reed screen type electrode. CONSTITUTION:A surface acoustic wave element 10 includes a reed screen type electrode 11 plus the same type electrodes 12A and 12B which are set at both sides of the electrode 11 respectively on a piezoelectric substrate. The electrodes 12A and 12B are electrically connected to each other by lead wires 13A and 13B. A relation shown by an equation is defined for spaces L1 and L2 between the center electrode 11 and the electrodes 12A and 12B respectively. In case when the number of pairs of electrode fingers is set at 50, the maximum Q is set at 100 with 50OMEGA reactance. As an inductance element can be formed in a small size on the piezoelectric substrate, the miniaturization is possible for the constitution of a filter, etc. with improvement of characteristics and a reduction of the cost. |
