LGS上的SAW滤波器特性实验研究

Experimental Investigation on SAW Filter Using Langasite Substrate

介绍了通过硅酸镓镧(LGS)上的滤波器试验,证明LGS基片具有与水晶相似的优良温度稳定性,而机电耦合系数是水晶的2～3倍,衍射影响几乎可以忽略,非常适合设计制作窄带低损耗高带外抑制滤波器。最后给出了欧拉角为(0°,140°,25.5°)的LGS切型制作的声表面波(SAW)滤波器频响曲线和温度特性曲线,发现在20°C附近频率温度系数存在拐点,即频率温度系数为0。

Langasite (LGS) has an excellent temperature stability compared with quarts.Its k2 is 23 times larger than quartz,and the diffaction effect is almost negligible.Experiment result on LGS SAW filter shows this material is very applicable for narrowband,lowloss SAW filter with high outband suppression.The frequency response and the temperature curve of LGS with Euler angles of (0°,140°,25.5°) is given.Zero temperature coefficient of frequency (TCF) can be find at around 20 °C.