Finite element design of CNT-based multilayer absorbers

Abstract

Purpose – A design procedure for multi-layer absorbers based on carbon nanotubes (CNT) frequency selective surfaces (FSS) sheets is here developed. The paper aims to discuss there issues. Design/methodology/approach – Single layer FSS are first analyzed via finite element (FE). Then equivalent sheets admittances are extracted in a transmission line model. Neural networks (NNs) interpolation over this data and subsequent multi-objective genetic algorithm (GA) based optimizations are then performed to design multiple layers absorbing structures. Designs are finally validated via full wave FEM simulations. Findings – In this paper, some absorbing structures made of three or four FSS sheets with total thicknesses around 6 mm are synthesized. Research limitations/implications – NNs' accuracy used in the equivalent model can be refined with further training. Practical implications – Low profile absorbing materials are of relevant industrial interest both for radar cloaking and anechoic chambers. Originality/value – The transmission line model combined with NNs and GA optimization is capable of speeding up the design procedure with respect to a conventional full-wave FEM approach.