Microwave absorption performance enhancement using glass fiber-reinforced polymer nanocomposites containing dielectric fillers in X-band

Microwave absorption properties of radar absorbing structures in X-band frequency have been investigated using carbon-based dielectric filler materials. These structures are composed of E-glass/epoxy laminates filled with various wt% (0–2.5 with an increment of 0.5) of graphene and multiwalled carbon nanotubes individually. Composite fabrication has been done using high-pressure resin transfer molding (HPRTM). The pertinent electromagnetic (EM) parameters of composite structures are measured using the waveguide measurement technique in X-band. From the results, a single-layered polymer composite with 2.5% graphene contains better absorption than others. Among multilayered structures, the 11-layered composite structure has shown the best absorption performance (reflection loss (RL) = −21 dB) which is equal to 99.9% of incident EM radiation absorption in X-band. It is found that the single-layered structure has shown ineffective absorption performance compared to the multilayered structure under low weight concentrations. Moreover, a mathematical model to predict RL of different combinations of multilayered structures based on EM wave theory is proposed for the calculation of optimum layer combination for minimizing time and money. The predictions of the mathematical model are validated for the 11-layered structure using experimentation.