Study On Laminated Cascade For Substrate Integrated Waveguide Dual-mode Filters

Microstrip line and rectangular waveguide are two very important transmission line, each ofthem has obvious advantages and disadvantages what can not be ignored. Microstrip line haslight weight, small volume, low cost, convenient integration and so on, but its loss is big such assmall power and low Q value. Rectangular waveguide not only has with high Q value, highpower, but also high cost, large volume and inconvenient integration. The development ofcommunication in twenty-first Century, transmission line and microwave filter is required moreand more strictly, and the transmission line and the filter's performance also determines thequality of communications. Substrate integrated waveguide ( SIW ) emerges as the times require,it synthesizes the microstrip line and rectangular waveguide substrate integrated waveguideadvantage, so not only good performance, but also facilitate the integration.In this thesis, the substrate integrated waveguide propagation characteristics is studied andLaminated substrate integrated waveguide dual-mode band-pass filter is designed.To design a high performance multi-cavity dual-mode band-pass filter by cascadingsingle-chamber dual-mode filters. Two kinds of cascade is discussed in this thesis, the first one isconnected through a strip line, this way has the advantages of simple structure and does notdamage the cavity, but the insertion loss is big, and so is the height. The second one is connectedby a planar waveguide, it is like the former one, however its insertion loss is bigger. The last oneis connected with the punch, this method ensures the cavity is closed, the height is short, but thedestruction of the original cavity the structure, which makes it difficult to regulate. Finally, twofour-chamber filters are designed by combining the two kinds of cascade.