On space mapping optimization with coarsely-discretized EM coarse models

Coarse model is a critical component of the space mapping (SM) optimization algorithm. It should be fast and reasonably accurate. A popular choice of the coarse model is an equivalent circuit. Circuit models are computationally cheap but they are not always accurate, and in many cases (e.g., antennas) they are not available. Coarsely-discretized EM models are available for all structures, they are reliable, but typically too expensive to be efficiently used in SM algorithms. Here, a study of SM algorithms with coarsely-discretized EM coarse models is presented. In particular, new and efficient parameter extraction and surrogate optimization schemes are proposed that make the use of coarsely-discretized EM models feasible for SM algorithms. Robustness of our approach is demonstrated through the design of two microstrip filters and a double annular ring antenna.