声表面波式小波变换器件的三次行程反射信号的研究

Study of Triple-Transition-Reflection Signal for Wavelet Transform Element of SAW Type

本文提出了用同相位法减小三次行程反射信号的方法.当信号频率与叉指换能器中心频率相等,并且主信号的相位等于三次行程反射信号的相位时,从可达到减小三次行程反射信号的影响.并且探讨了双接收叉指换能器并联法,要求双接收叉指换能器要完全对称,否则声表面波式小波变换器件频率特性曲线不光滑.

The method of reducing triple-wansition reflection signal with the same phase method is proposed in the paper. When the frequency of the signal equals the center frequency of iterdigital transducer （IDT）,the phase of the main signal equals the phase of triple-transition reflection signal,so that the triple-Wansition reflection signal is roduced. And the parallel method of the double receiving IDTs is studiod. The double receiving IDTs are absolutely symmetrical, otherwise the frequency characteristic curve of wavelet Wansform element of SAW type is not smooth.