该文设计了一款用于电子不停车收费系统(ETC)的声表面波(SAW)滤波器。该款滤波器采用3-1-3分节的电容加权结构和电极宽度控制(EWC)的换能器单元结构，基片材料为128°Y-X铌酸锂。通过对滤波器外围匹配电感、换能器反射指结构和膜厚的优化，实现了滤波器小插入损耗和高阻带抑制，制作滤波器的中心频率为40 MHz，插入损耗为-7.5 dB。该文突破常规设计方法，采用在扇形结构中换能器全抽指加权SAW滤波器的设计手段，使器件最终满足ETC项目使用要求。

This paper introduces the design method of a surface acoustic wave filter for electronic toll collection system (ETC). The filter adopts 3-1-3 segment capacitance-weighted structure and electrode width control(EWC) transducer unit structure. The substrate material is 128°Y-X lithium niobate. Through optimizing the filter peripheral matching inductance, the transducer reflection finger structure and film thickness, we design a filter with center frequency of 40 MHz, small insertion loss of -7.5 dB and high stopband suppression. Breaking through the conventional surface acoustic wave filter design method for the first time, the design method of the transducer full withdraw weighting in the fan-shaped structure is adopted, and the finally fabricated devices meet the use requirements of ETC project.