一种抽头式交指带通滤波器的设计及实现

传统的交指带通滤波器设计采用公式计算归一化自电容和互电容,并通过查表计算得到滤波器的参数,该方法计算繁琐,且计算误差较大.文中介绍了一种根据谐振器的直接耦合原理,利用两终端的外部品质因数Q和谐振器间的耦合系数K设计抽头式交指型带通滤波器的方法.据此,设计了一种用于微波选频的交指滤波器,借助ADS软件对滤波器进行仿真和优化.通过仿真及实测结果的分析对比,进一步给出了设计改进方案.

Design of Microstrip Tapped-Input Interdigital Bandpass Filters

The traditional method to design interdigital filter,which obtains the filter parameters from calculating self-capacitance,mutual capacitance and Look-up table,proved to be complicated and inaccurate.In this paper,a new method utilizing external quality factor Q and the inter-resonator coupling coefficient K was introduced.As a sequent,an interdigital filter was designed for the microwave frequency-selector.The simulation results were compared with the experimental results.Further,the modulated method for bandpass filter was presented in detail.