平行耦合微带线带通滤波器分析与设计

摘要

为了克服平行耦合微带线带通滤波器设计中存在的尺寸大、需要查表、优化困难等问题，提出了一种平行耦合微带线带通滤波器基于ADS软件的设计方法。经过深入的理论分析发现，平行耦合线带通滤波器系统阻抗微带线非谐振单元，长度可尽量取短以减小电路尺寸；利用ADS软件自带滤波器设计工具可得到低通滤波器原型，省去了查表的麻烦；在版图优化上采用调谐方法比优化方法更有效。仿真结果表明，所设计带通滤波器系统阻抗微带线为2．5 mm，中心频率5 GHz，相对带宽10％。该方法在减小滤波器尺寸的同时没有降低滤波器性能，设计实现快速高效。%In view of large size,table checking required and difficult optimization in the design of parallel coupled microstrip line bandpass filter,a design method of parallel coupled microstrip line bandpass filter based on ADS is proposed.Based on thorough theoret⁃ical analysis,it is found that the parallel coupled microstrip line bandpass filter system impedance microstrip line is not resonant,so the length can be as short as possible to reduce the circuit size.A prototype of a lowpass filter is obtained by using ADS software,eliminating the trouble of the look⁃up table;In the layout optimization,the tuning method is more effective than the optimization method.The simula⁃tion results show that the system impedance microstrip line is 2.5 mm long,the center frequency is 5 GHz,and the relative bandwidth is 10%.This method can reduce the size of filter and not reduce the performance of the filter.The design and implementation of this method is fast and efficient.