采用分组单指结构的高性能声表面波滤波器

A High Performance SAW Filter Using Single-Finger Grouping Structure

介绍了一种无指间反射的分组单指换能器结构，它具有分裂指相同的ＴＴＳ效果，而工艺难度得以降低。首次将变迹加权用于该结构，制作了高带外抑制的滤波器，并给出了试验结果。中心频率４１８ＭＨｚ，相对带宽２‰，阻带抑制优于３８ｄＢ，插入损耗１８ｄＢ。

This paper presents a single-finger grouping structure of transducer without interfinger renection, which has the same TTS effectiveness as that of split-finger and reduces the process difficulty. The apodized weighting is first applied on this kind of transducer structure in ourwork, and a SAW filter with high out-of-band rejection is produced. The experimental results areas followes:center frequency=418 MHz, relative bandwidth=2 ‰, out-of-band>38 dB, insertionloss=18 dB.