Multi-level design optimization of microwave structures with automated model fidelity adjustment

Automated procedure for multi-level optimization of microwave structures is proposed. Our approach exploits variable-fidelity electromagnetic (EM) simulations, an efficient algorithm for optimizing simulation-based models built with local response surface approximations, as well as automated adjustment of model fidelity. Convergence of the procedure to the optimum design is ensured by defaulting to the higher-fidelity model whenever the prediction given by the lower-fidelity fails to improve the design. The operation and performance of the proposed technique is demonstrated through design of a bandpass filter and a dielectric resonator antenna.