Fabrication and optimization of radar absorbing structures composed of glass/carbon fibers/epoxy laminate composites filled with carbon nanotubes

The radar absorbing structures (RAS), which cannot only load bearing but absorb electromagnetic wave energy by inducing dielectric loss and minimize reflected waves, is a multifunctional composite. Therefore, many researchers have paid attention on the development of RAS. The essence of the RAS was reducing RCS of the object. The composites possess excellent specific stiffness and strength. The electromagnetic wave properties of the RAS can be tailored by controlling the content of the lossy materials. Radar absorbing structures laminate composites, which were composed of glass fibers, carbon fibers and epoxy resin filled with carbon nanotubes, were fabricated in a press mould. In the paper, the complex permittivity of the RAS laminate composites was measured by free shape measurement system, and the absorbing properties were simulated based on electromagnetic theory. As a result, two optimal double-layer RAS was obtained. The reflection loss was less -10 dB in entire X frequency, and the lowest was -26.6 dB.