SAW式WTP输入及输出阻抗匹配研究

Study on the Input and Output Impedance Matching in SAW-type WTP

由于组成声表面波(SAW)式小波变换处理器(WTP)的叉指换能器的等效电路是一个三端口网络,因而其插入损耗和三次渡越反射都与输入、输出阻抗有关且相互影响。为此,在将该芯片用于电子系统中时,必须对其输入、输出阻抗匹配进行研究,以在抑制其多次声波反射的同时保证其插入损耗尽可能地低。因此,该文提出了利用SAW式WTP的导纳矩阵计算其输入、输出阻抗,并由此设计其匹配网络的方法。理论研究和实验结果表明,利用这种方法设计的SAW式WTP的匹配网络,可以使该器件的插入损耗降低30%以上。

Since the equivalent circuit of the interdigital transducer (IDT) that constitutes the SAW-type wavelet transform processor (WTP) is a three-port network, the insertion loss and triple transit of the SAW-type WTP are both related to input and output impedance and interact with each other. For this reason, when using this chip in an electronic system, it is necessary to study its input and output impedance matching to suppress its multiple acoustic reflections while ensuring its insertion loss is as low as possible. Therefore, this paper proposes a method of calculating the input and output impedance of the SAW-type WTP by using the admittance matrix and designing its matching network. The theoretical study and experimental results show that the SAW-type WTP matching network designed the proposed method can reduce the insertion loss by more than 30%.