Electromagnetic and radar absorption characteristics of iron/epoxy polymer composites based on dispersion and mixing ratios of iron particles with different particle sizes

This study proposes a single-layer radar absorber using iron (Fe) powder and epoxy. Two types of Fe particles with different particle sizes were utilized as fillers to impart electromagnetic(EM) properties to the epoxy. These two types were mixed in weight fractions of 8:2, 8.5:1.5, 9:1, 9.5:0.5, and 10:0 and dispersed in epoxy. The dielectric loss tangent and magnetic loss tangent of the five types of Fe particles/epoxy mixtures were measured using a coaxial waveguide, and the trends in EM properties according to the mixing ratios were analyzed. Based on the EM properties of the five mixtures, single-layer radar absorbers were designed for each material to investigate the changes in absorption performance relative to absorber thickness. Among the five mixtures, the 8.5:1.5 ratio demonstrated the widest radar absorption bandwidth and the best absorption performance. By optimizing the design of the Fe particles/epoxy radar absorber with an 8.5:1.5 mixing ratio, tuning to the target frequency can be effectively achieved under the designer’s specifications to maximize absorption performance over the desired bandwidth. The Fe particles/epoxy radar absorber proposed in this study is expected to achieve radar absorption performance with reduced thickness, potentially finding applications in various industries.