Design of Cavity Filter Based on Multi-port Parameter Extraction and Aggressive Space Mapping

An efficient design method for microwave filters based on multi-port parameter extraction and space mapping is presented in this paper. Firstly, the coupling matrix through Y parameters of the multi-port filter electromagnetic model added from addtional internal ports is computed. Then, the problem of finding optimal size of filter is transformed into the problem of approximating ideal coupling matrix. Finally, a fourth-order coaxial cavity filter is designed and fabricated. The physical size of the filter can be obtained after four iterations under the condition that the initial value deviation is large. The real debugging results and the simulation results are in good agreement, which proves that the proposed method is fast and effective.