Efficient Design of Inline E-Plane Waveguide Extracted Pole Filters Through Enhanced Equivalent Circuits and Space Mapping

A design procedure for inline waveguide extracted pole filters with all-metal E-plane inserts is presented. To achieve acceptable modeling accuracy for this class of filters, an enhanced schematic-circuit-based surrogate model is developed, accounting for parasitic effects between the neighboring elements of the structure. The proposed circuit representation is used as a coarse model in a surrogate-based optimization of the filter structure with the space mapping technique as the main engine in the optimization process. Feasibility of the modeling approach is demonstrated by two filter design examples. The examples show that a low computational cost (corresponding to a few evaluations of the high-fidelity EM simulations of the filter structure) is required to obtain an optimized design.