Effect of Activating Agent on Electromagnetic Waves Absorption of Carbon-based Radar Absorber Material

Low cost electromagnetic wave absorbers using carbon-based materials are very interesting in development of an anechoic chamber. In this work, the effect of various types of activating agent on carbon-based Radar Absorber Materials (RAM) will be presented. The carbon materials used in this study comes from 4 types of natural materials, namely coconut shells, oil palm shells, cocoa pods, and rice husks. Meanwhile, the activating agent consist of KOH and HCL are operated in carbon activating. The effect of concentration variations of the activating agent on the electromagnetic wave absorption also investigated on all types of carbon materials. The activated carbon materials are characterized to inspect the absorption of electromagnetic waves in the frequency center 8 GHz using a Vector Network Analyzer (VNA). The experiment results showed the optimum absorption in that rice husk and coconut shell was obtained using the HCL activating agent. On the other hand, the maximum absorption for cocoa pods and oil palm shells carbon was obtained by KOH activating agent. It can be concluded that the absorption of electromagnetic waves of a carbon material is dependent on the type of activating agent.