Low‐fidelity model considerations for simulation‐based optimisation of miniaturised wideband antennas

Abstract

Here, variable-fidelity electromagnetic (EM)-based design optimisation of miniaturised antennas is discussed. The authors focus on an appropriate selection of discretisation density of the low-fidelity EM model, which results in good performance of the optimisation algorithm in terms of its computational complexity and reliability. Trust-region gradient search with low-fidelity model corrected by means of non-linear frequency scaling and multiplicative output space mapping is utilised as a benchmark optimiser. Comprehensive studies are conducted for several structures of planar wideband antennas, optimised for best matching and minimum size. The results indicate that appropriate low-fidelity model set-up can be determined by means of a correlation analysis based on selected characteristic points of the antenna responses and sparsely allocated test designs.