基于EMSIW-QMSIW小型化带通滤波器设计

Design of miniaturized bandpass filter based on EMSIW-QMSIW

为有效减小S波段基片集成波导(Substrate Integrated Waveguide,SIW)滤波器的尺寸和插入损耗,提出了一种基于四分之一模基片集成波导(Quarter-Mode Substrate Integrated Waveguide,QMSIW)和八分之一模基片集成波导(Eighth-Mode Substrate Integrated Waveguide,EMSIW)交叉排列耦合的小型化带通滤波器;并针对提高滤波器选择性和带外抑制水平,通过设计源与负载耦合,实现传输零点的引入。设计了一款小型化带通滤波器,中心频率为3.7 GHz,相对带宽为18.9%,仿真测得最小插入损耗为0.55 dB,带外抑制大于40 dB,且标准化尺寸仅为0.24λ_0×0.11λ_0。通过制作实物验证,测试与仿真相吻合。

In order to reduce the size and insertion loss of S-band substrate integrated waveguide(SIW)filters,a miniaturized bandpass filter was proposed based on cross-arrangement coupling between 1/4 mode substrate integrated waveguide(Quarter-Mode Substrate Integrated Waveguide,QMSIW)and 1/8 mode substrate integrated waveguide(Eighth-Mode Substrate Integrated Waveguide,EMSIW).In order to improve filter selectivity and out-of-band suppression level,the transmission zero was introduced by source-load coupling.A miniaturized bandpass filter was designed with a center frequency of 3.7 GHz,a relative bandwidth of 18.9%,a minimum insertion loss of 0.55 dB,an out-of-band suppression of more than 40 dB and a standardized size of 0.24λ0×0.11λ0.Through physical verification,the test results are in good agreement with the simulation results.