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本文报道了作者研制的频率范围分别为200—350MHZ和350一500MHZ的两种15信道声表面波滤波器组的结果。为了克服现有技术温度稳定性较差的缺点，基片材料采用Yll2°LiTaO3，温度稳定性比现有技术提高3．5—5倍。每个滤波器中的两个叉指换能器一个采用特殊抽样的单指换能器，另一个采用三次谐波工作的分裂指换能器，从而避免了采用基频工作的分裂指换能器所需的0．8μm。工艺。输入匹配网络采用改进的串并联匹配网络，降低了输人匹配网络的插人损耗，补偿了因采用Yll2°LITaO3，单个滤波器插损较大的缺陷，使滤波器组总的插入损耗与现有采用YZ或Y128°LiNbO3的滤波器组相当。
This paper reports the results of two 15-channel SAW filter banks developed by the authors in the frequency range of 200-350 MHz and 350-500 MHz, respectively. In order to overcome the shortcomings of the prior art, such as poor temperature stability, the substrate material adopts Yll2 ° LiTaO3, and the temperature stability is improved by 3.5 to 5 times than the prior art. One of the two interdigital transducers in each filter uses a specially-sampled one-finger transducer and the other uses a third-harmonic working split-finger transducer, thereby avoiding split-finger switching using fundamental frequency The required 0.8μm. Process. The input matching network adopts an improved series-parallel matching network, which reduces the insertion loss of the input matching network and compensates for the defect that the insertion loss of the filter bank is larger due to the use of Yll2 ° LITaO3. A filter bank with YZ or Y128 ° LiNbO3 is equivalent.