Thickness optimization of water hyacinth (enceng gondok) as a dielectric single-layer absorber radar absorber material

This study investigated the potential of water hyacinth-derived biocarbon as a single-layer radar absorbing material (RAM) in the X-band frequency range through thickness optimization via a genetic algorithm (GA). The biocarbon was synthesized via carbonization and characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), and electromagnetic measurements via the Nicolson–Ross–Weir (NRW) method. The XRD results indicated that the material was predominantly amorphous, whereas the SEM observations revealed a porous morphology with irregular cavity-like structures formed during carbonization. Electromagnetic characterization revealed relatively stable permittivity behavior with a weak magnetic response, suggesting that dielectric loss is likely the dominant microwave attenuation mechanism. Reflection loss analysis revealed a minimum RL value of approximately − 11.65 dB at 9.7 GHz, with an optimized absorber thickness of approximately 1.53 mm. Compared with the nonoptimized configuration, the optimized structure exhibited improved impedance matching behavior. These findings suggest that water hyacinth biocarbon has potential as a lightweight and environmentally friendly microwave absorbing material. However, further studies involving wider frequency ranges and more complex absorber configurations are still needed to improve the absorption performance.