Investigations On The W-Band Substrate Itergrated Filter

With the development of wireless communication system, W-band (75-100GHz) has attracted widely attention due to its super wide bandwidth. In recent years, millimeter-wave filters, being the key module in RF systems, have been widely concerned by many scholars. Therefore, this paper makes a study on the low cost W-band planar filters.On the other hand, the substrate integrated waveguide (SIW) devices are composed of a large amount of metallic vias, which require high-density meshing associated with large number of unknowns. A lot of time and computer resources will be consumed. In order to overcome this challenge, the aggressive space mapping (ASM) algorithm has been adopted in this paper. Circuits and electromagnetic full wave simulation model are set up by using ADS and HFSS, which are adopted for coarse and fine simulation models for the space mapping algorithm, respectively. The software Matlab is used to establish the mapping relationship between two models. The dissertation is organized as follows:Firstly, the paper introduces the application background of W-band and the development of SIW technology. At the same time, the basic theory of filter synthesis and space mapping algorithm are reviewed, which lays the foundation for the design procedure of this paper.Secondly, the research of the W-band SIW to rectangular waveguide interface is carried out. Two kinds of transfer structures are designed and fabricated, including the traditional vertical transfer and a novel simple fin-line structure. Experimental results verify the correctness of the design, which lay a foundation for the measurement of W-band SIW filters.Finally, a variety of structure forms of W-band SIW filters are designed by combining the coupling matrix theory and aggressive space mapping method. The final filter responses are obtained by connecting the fin-line or the vertical transfer. In order to verify the simulations, the designed filters are processed by using low cost PCB techniques. The experiment results show that the designed SIW filters have the advantages of compact size, low insertion loss, high selectivity. Additionally, the tolerance analysis is carried out for the filter with fin-line structure, and the accuracy of the simulation is verified. It also shows that high performance W-band filters can be obtained by using low cost PCB techniques.