Optimization of multilayered electromagnetic shielding using mesh adaptive direct search

Multilayered composite structures have been proven to have superior shielding properties, compared to bulk composites if the layers’ thicknesses and effective permittivities are set in a way to utilize internal multireflection in a layered structure in frequency ranges of required specific transmission or absorption spectra. Those spectra are practically objective functions used in many mathematical optimization algorithms. In this work, the modified mesh adaptive direct search (MADS) algorithm has been used to design 4-layered composite structures with as high as possible absorption and frequency filtering of electromagnetic radiation (EMR). The set of multilayered samples was optimized to achieve (i) the lowest reflection loss in the range of 30–40 GHz and (ii) the EMR filtering. The optimization with MADS algorithm has shown that broad absorption bands with bandwidths Δf_10 dB up to 40 GHz and deep reflection loss RL_min down to − 40 dB can be obtained by composite structures of thicknesses up to 2 mm with 3 or 4 nanocarbon/inorganic filler/epoxy resin composite layers. The obtained results show the possibility to design composite structures with specific shielding spectra, but the composite layers’ fabrication inaccuracies may lead to significant mismatches between measured and modeled spectra.