Improved variable-fidelity optimization algorithm for simulation-driven design of antennas

An improved version of the variable-fidelity optimization technique for the simulation-driven design of microwave structures including antennas is presented. It exploits a set of electromagnetic(EM)-based models of increasing discretization density that are sequentially optimized with the optimum of the “coarser” being the initial design for the “finer”. The final design is refined using a polynomial-based approximation model constructed from the coarse-discretization simulation data. The coarse-discretization models are optimized using a novel algorithm that allows us to reduce the overall design time by up to 50% when compared to the original version of the method. The presented technique is particularly suitable in cases where simulation-driven design is the only option. Operation of our approach is demonstrated using two examples of broadband antennas. In all cases, the optimal design is obtained at a low computational cost corresponding to a few high-fidelity simulations of the structure.