Design and verification of the square convex surface multilayer radar absorbing structure based on additive manufacturing

This paper presents a novel approach to addressing electromagnetic property variations in 3D printed structures using additive manufacturing (AM). Utilizing continuous fiber 3D printing, the focus is on designing and fabricating a square convex surface multilayer radar absorbing structure (RAS) tailored for obliquely incident electromagnetic (EM) waves. Variations in complex permittivity due to structural shape-influenced changes in nozzle paths in AM-fabricated 3D printed structures are observed. To counter this, a ‘Process Permittivity Correction Method’ is developed, enhancing design and fabrication accuracy. Before optimizing each structure of the RAS, the process permittivity, which varies according to the structural shape and the set nozzle paths, was applied in the design. The optimized RAS, considering both TE and TM modes at a 60° incident angle, showed a high correlation between the trends of interpreted and measured absorption performance. This approach effectively corrects electromagnetic property variations in 3D printed structures, ensuring consistency between design and manufacturing while maintaining EM properties and absorption performance.