PURPOSE: To increase the performance by rejecting the unnecessary reflection signal, through the formation of the auxiliary electrode with the direction of propagation and specific angle from the side of opposing with the piezoelectric substrate end of the reed screen type electrode having the auxiliary electrode to the electrode finger having maximum crossing width of the weighting electrode.
CONSTITUTION: Over the entire region of the weighted electrode 11, the reed screen type electrode provided with the auxiliary electrodes opposingly is placed on the piezoelectric substrate. The weighted electrodes take the electrode finger having the maximum for the corssing width as boundary (dotted lines 13, 13') the auxiliary electrode sections 21 and 22 at the effective delivery line of the opposing surface acoustic wave are vertical toward the direction of propagation and are formed parallelly with the electrode finger of the weighted electrode. The angles θ 31 and 32 taking the dotted lines 13 and 13' as boundary and the effective delivery direction of the electrode finger of the auxiliary electrodes 23 and 24 at ineffective delivery line of the surface acoustic wave are set as respectively 90°<θ<180° and -180°<θ<-90°. With this constitution, the reflection waves caused with the auxiliary electrode are not incident to the weighting electrode with the in-phase and the reflection waves are rejected, and the frequency performance and timing performance is increased.
YAMADA JIYUN
HAZAMA TAKESHI
NORO YOSHIHIKO
| JPS5469359A | 1979-06-04 |
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