Rapid design optimization of miniaturized rat-race coupler using multi-fidelity electromagnetic models

The paper presents a technique for fast design optimization of compact microwave structures using multi-fidelity electromagnetic (EM) simulations. In our approach, sequential optimization of EM models of increasing fidelity is supplemented by a design refinement step exploiting fast response surface approximation model and space mapping. The technique is demonstrated by the design of a rat-race coupler.