基片集成波导带通滤波器交叉耦合技术分析word格式论文.docxVIP

AbstractCombining the inherent advantages of waveguide resonator filter namely high quality, high power capacity and the advantages of micro-strip line namely light weight, small size, cheap price and easy to be integrated, Substrate Integrated Waveguide (SIW) filters become popular for filter design in the past decade. In general, there are two ways to maintain transmission zeros (TZs), that is cross-coupling technique and muti- mode technique. As another key point, crossing coupling technique, which adds extra coupling between non-adjacent resonators, is theoretical and practical.Firstly, based on the canonical topology of cross coupling resonator, stacked four-cavity SIW bandpass filters, with input and output laying on the same layer, are achieved. Detailed discussions of the impacts of the coplanar microstrip input/output structure, non-coplanar probe input/output structure and the coupling slot, coupling circle are made to modify the design parameters. Furthermore, taking price and difficulty into account, fabrication of the 2.5GHz SIW bandpass filter using cross coupling technique with micro-strip input/output ports has been done. Measured results basically agree with the simulation, showing the 2% narrow bandwidth and 2.47GHz centre frequency. Moreover, the influence of the relative layout of resonator cavities for filter design and a improved layout is demonstrated according to the analysis and verification of stacked three-cavity SIW filter.Secondly, in order to study the SIW bandpass filter based on another cross coupling topology, coplane four-cavity and stacked four-cavity SIW bandpass filters are proposed. The simulation results show that these two cross coupling topologies four-cavity SIW filters have the same performance. Especially for the new coplane four-cavity SIW cross coupling filter, it shows a good character when it works at different modes such as the the dominant mode, high mode or both modes. In addition, the stacked four-cavity SIW cross