Design of Ferrite-Graphene-Based Thin Broadband Radar Wave Absorber for Stealth Application

Currently, a wide range of materials are used for radar wave absorption. But it is still a very challenging task to develop a thin radar wave absorber that operates for a wide range of frequencies. The main objective of this paper was to achieve good absorption with wide bandwidth corresponding to reflection loss (RL) <=-10 dB for lower thickness (<= 2 mm) by developing ferrite-graphene (FG) composites. A critical study has been carried out by varying the composition of FG to obtain wideband absorption with lower thickness. The effective complex dielectric permittivity (mu', mu '') and effective complex magnetic permeability (epsilon', epsilon '') of composites were measured using transmission/reflection waveguide method in the range of 8.2-12.4 GHz. These measured epsilon', epsilon '', mu', and mu '' values have been used for the design of single- and double-layer absorber. Increasing the graphene content in FG composites resulted in a reduction of thickness and wide absorption bandwidth. Furthermore, a multilayer approach is adopted to enhance the radar wave absorption with broad bandwidth at a lower absorber layer thickness. The double-layer absorber shows a strong RL of -55.28 dB at 10.2 GHz with broad bandwidth of 3.1 GHz in the frequency range of 8.6-11.7 GHz. The multilayering approach facilitated to attain a lower absorber layer thickness of 1.7 mm. Findings provide an effective and feasible way to develop a thin and broadband absorber, which may be utilized for stealth applications.