一种改进型微带交指滤波器的仿真设计

摘要

针对微带交指滤波器KQ法及奇偶模阻抗法设计不够精确、不够简便的问题,研究了一种基于自互电容的终端短路式微带交指滤波器的设计方法,给出了详细的设计步骤及仿真设计实例.提出了一种微带交指滤波器的改进结构,该结构通过在交指滤波器的中间耦合节上增加一段λ08的微带线,使滤波器的3dB带宽从100MB减小到40 MB,带内抖动减小了2.7 dB,阻带衰减增加了2dB左右,该仿真结果证明了改进结构的有效性.%To overcome the inexactitude and inconvenience of KQ method and parity module method, this thesis researches a designing method of terminal short-circuited microstrip interdigital filter based on self-mutual capacitance, gives detailed designing steps and example of simulation design. This paper puts forward an improved structure of microwave interdigital filter, this structure adds a microstrip line whose length is λ0/8. This structure makes the 3 dB bandwidth decrease from 100 MB to 40 MB, passband dithering decrease 2.7 dB, stopband attenuation decrease about 2 dB, this simulation result shows that this improved structure is in effect.