采用新型介质集成波导腔的小型双频滤波器

提出了一种新式的横电磁波-基片集成波导(TEM-SIW)谐振腔。这种TEM-SIW谐振腔由经典的基片集成波导(SIW)腔发展而来。通过在SIW腔的中心位置加入短路销钉,将SIW腔体的上金属平面与腔四周导体壁开路构成TEM-SIW腔。相同谐振频率下,单个TEM-SIW腔的面积可以减小到传统的SIW谐振腔面积的9.5%。分析了主模式工作情况下TEM-SIW谐振腔和传统的SIW谐振腔的结构以及腔内的磁场分布。由于其磁场分布与工作在TEM模式的电容加载同轴腔相似,因此,基于这种谐振腔的滤波器可以很方便的借鉴经典的电容加载同轴腔滤波器的耦合结构和综合设计技术。最后,设计了一个基于TEM-SIW腔的三级双频滤波器,其性能已经通过了数值仿真和实验验证。

Novel compact dual-band bandpass filter adopting SIW cavity

A novel transverse electromagnetic-substrate integrated waveguide(TEM-SIW)cavity is presented in this paper.The TEM-SIW cavity is developed from traditional SIW cavity.Through inserting a short metal pin into the centre of the SIW cavity and opening the top metal plane of the SIW cavity to its metal side-wall,the TEM-SIW cavity can be achieved.The size of the TEM-SIW cavity can be reduced to 9.5% of the traditional SIW cavity in the same resonant frequency.Then this paper analyzes the structure and magnetic field distribution of TEM-SIW cavity and traditional SIW cavity in the dominant mode.The magnetic field distribution of TEM-SIW cavity is found to be similar with those of the capacitor loaded coaxial-cavity in the TEM mode.Therefore,the coupling structure and designed techniques for the classical capacitor loaded coaxial-cavity filters can be easily used in the filters with the TEM-SIW cavities.Finally,a dual-band bandpass filter(BPF)adopting TEM-SIW cavity is designed and presented in this paper,and the performance of the designed dual-band bandpass filter is validated numerically and experimentally.