Study And Design Of Filter Based On Substrate Integrated Waveguide(SIW)

In recent years, the SIW(Substrate Integrated Waveguide) structure has stimulated an unprecedented enthusiasm in both academia and industry. As a novel guide wave structure, Substrate Integrated Waveguide is a synthetic rectangular waveguide formed by the top and bottom metal plates of a dielectric slab and two sidewalls of period metallic via-holes. It has lots of advantages such as low profile, high Q factor, high power capacity, easy fabrication and good integration on planar circuits, etc. Thus, SIW has been widely used in microwave and millimeter wave circuits fields. And it has been a hot research topic to the design and research of filters using SIW technology in recent years. The author’s major contributions are outlined as the follows:Firstly, the basic theories about the filter are discussed in this paper, which are the foundation for the design of SIW filter in later chapters. It includes the basic working principle of the filter, the basic indicators parameters, the basic model and the transfer function of the filter. And the Network Synthesis method of designing filter is described. In this section, the low-pass prototype filter is a more focused object, because it is the basis for the design of other filters.Secondly, the structural characteristics and types of SIW are introduced. And the similarities and differences between the SIW structure and the waveguide structure are compared. The author also analyzes SIW circuit characteristics and design methods. And several typical SIW- microstrip transition structures are introduced. The simulation is designed for each structure. And then, this paper introduces characteristics and scope of these structures. These structures have been used in the conversion later.Then, in this paper, the Defected Ground Structure unit is introduced, and its three equivalent models are studied. We analyze its transmission performance and summarize its application. Based on the above theories, we combinethe structure of the Defect Ground Structure and the structure of the Substrate Integrated Waveguide. And the theories and methods of the design of the SIW filters based on the structure of the Defected Ground Structure are studied. And we design a SIW filter based the structure of the Defect Ground Structure, the final simulation and measurement results are better.In additions, in order to achieve the compact design of this filter, the dual-mode SIW filters are designed in this part. After discussing the structure and transport properties of the square Substrate Integrated Waveguide resonators, a dual-mode Substrate Integrated Waveguide filter is realised by perturbing degenerate mode through two metallic vias. The filter is simple in structure, easy processing, and has better performance. The final simulation and measurement results can meet the design specifications.Finally, in order to achieve further miniaturization of Substrate Integrated Waveguide filter, the another two Substrate Integrated Waveguide dual-mode filters are designed. In the filter designed in the last past of this paper, a "crossover" slot line is introduced. Thus, the volume and quality of the filter are reduced successfully. The other SIW dual-mode filter is realised by introducing a "T"-shaped minor. The size of the filter is further reduced, and it still has high Q, low loss characteristics. The final simulation and measurement results of these two filters are ideal to prove the correctness of the design method.