| 摘要 |
PURPOSE:To obtain a correlation signal with high signal quality by weighting the tap of an output electrode so as to equalize the levels of signals outputted from respective taps. CONSTITUTION:When a signal is impressed to an input electrode 12, a surface acoustic wave is excited and propagated to an output electrode 13. Respective taps 141, 142...14N are composed of one or plural pairs of electrode fingers, and only the surface acoustic wave arriving at the cross width range of the electrode fingers is related to exchange to an electric signal. As the weighting means of respective taps, the cross widths of the electrode fingers are made different so as to equalize the levels of the electric signals outputted from the respective taps. Namely, the cross width of an i-th tap (i) among the taps 141-14N is made wider than a tap i-1 while considering the decrease of SAW energy at the tap i-1 close to the input electrode 12. As a result, the levels of electric signals extracted from the respective taps are made equal. A proper correlated output can be provided by synthesizing and extracting the electric signals from these respective taps. |
