声表面波低插入损耗滤波器的研制(Ⅰ)——控制电极宽度单相单向换器

Design and performance of SAW low insertion loss filters (Ⅰ) single phase unidirectional transducer

摘要: 概述了控制电极宽度单相单向换能错的工作原理和设计方法;讨论了声波单向辐射的方向与柳条反射系数相位之间的关系;给出了作者在ST石英、Y112°LiTaO₃和Y128°LiNbO₃基片上研制的两种无线通信用中频滤波器和作无绳电话双工器使用的两种滤波器的实验结果.插入损耗分别为4.6dB、3.5dB和3dB;相对带宽分别为0.60%、0.75%和1.4%;阻带抑制均大于50dB.

Abstract: The principle and the design method of EWC/SPUDT is presented.The relationship that directivity of sAW excited unidirectionally on Ewc/SPUDT depends on the phase of the reffective coefficient of the reflective strip is discussed.The measured frequency response of the IF filters for wireless communications and the filters for antenna duplexer of Chinese CT1 fabricated on ST-X Quartz,y112° LiTaO₃ and Y128° LiNbO₃ substrates are presented.Their insertion loss are 4.6 dB,3.5 dB and 3 dB with bandwidth 0.6%,0.75% and 1.4% respectively and out-of-band rejections more than 50 dB.