Fabrication of multi-layer radar absorbing structures based on continuous fiber 3D printing and thickness correction method

Three-dimensional (3D) printing technology has revolutionized the fabrication of complex geometries, including electromagnetic wave absorbers. In this study, the multilayer radar absorbing structure (RAS) was designed and fabricated using a continuous fiber 3D printing process based on material extrusion (ME). However, a large thickness error occurred during the 3D printing process. The thickness error in the multilayer RAS, which is a resonant electromagnetic wave absorber, causes a large error in the electromagnetic wave absorption performance. To address this issue, the thickness correction method based on unit thickness was proposed. The unit thickness, which is the basic thickness of the multilayer RAS, was calculated to account for the thickness increase during printing. The redesigned RAS based on the calculated unit thickness effectively corrected the thickness error. The total thickness and thickness of each layer of the corrected RAS were measured and found to be similar to the design value. The measured electromagnetic wave absorption performance closely matched the analyzed value, confirming the effectiveness of the unit thickness-based correction method in improving the ME-based 3D printing process for fabricating RAS.