本文基于传统的SIR双频滤波器的优缺点,在分析四分之一波长SIR的基础上,提出了一种E型可调多枝节SIR双通带滤波器的设计方案,采用零度馈电结构引入三个传输零点,从而提高了频率的选择特性和阻带特性。采用了零度馈电结构,与传统双频滤波器相比,具有结构简单、更加紧凑、而且具有低插入损耗、高频率选择性的优良特性。设计的滤波器两个中心频率分别为4.23GHz和6.26GHz,实测插损分别为1.09d B和1.61d B,-3d B相对带宽分别为7.3%和2.4%,仿真与实测吻合良好。 Based on the advantages and disadvantages of the traditional SIR dual-band filter, based on the analysis of the quarter-wavelength SIR, a design scheme of E-type adjustable multi-branch SIR double-pass filter is proposed. The introduction of three transmission zeros increases the frequency selectivity and stopband characteristics. Adopting the zero-feed structure, it has the advantages of simple structure, compactness, low insertion loss and high frequency selectivity compared with the traditional double-frequency filter. The designed center frequency of the filter is 4.23GHz and 6.26GHz respectively, the measured insertion loss is 1.09d B and 1.61d B respectively, and the relative bandwidth of -3d B is 7.3% and 2.4% respectively. The simulation is in good agreement with the measured data.