Efficient full-wave CAD of waveguide diplexers

摘要

The paper presents an efficient CAD algorithm for the design of waveguide front-end diplexers. Three different types of junctions can be employed: E-plane T-junction, H-plane T-junction and E-plane bifurcation. Channel filter configurations currently include — but are not limited to — waveguide stub filters and inductive-iris filters. The diplexer design is performed in three basic steps: synthesis, analysis and optimization. In order to improve the computing efficiency of the design algorithm, highly accurate transmission line models are used in the initial component design and optimization stages. The final optimization and the analysis of the entire diplexer makes use of a full-wave mode-matching model, which can include waveguide transformers at all ports. The CAD routine is verified against measurments, and excellent agreement between predicted and measured results is obtained.