A Low-Cost Radar Absorber Based on Palm Shell Active Carbon for Anechoic Chamber

Abstract

Synthesis and characterization of a low-cost Radar Absorber Material (RAM) based on palm shells activated carbon is presented in this work. This low-cost RAM is intended to be used to cover the walls of the anechoic chamber. Palm shells are industrial waste from oil palm plantations and are widely available in West Sumatra. This work aims to investigate the characteristics of RAM based on palm shell for various types of an activating agent. In addition, the characteristics of RAM are also investigated due to the effect of the concentration of the activating agent. In this research, HCl, KOH, H3PO4, and ZnCl2 are operated to activate carbon of palm shell by opening the carbon pores. Characterization of the active carbon in term of absorption and morphological on the surface is performed by using a Vector Network Analysis (VNA) and a Scanning Electron Microscopy (SEM). The waveguide technique is operated in the investigation of the absorption of electromagnetic waves of the RAM on the C-band operating frequency (4 to 8 GHz). The measured results present the maximum absorption of the RAM is obtained -26.3 dB at a frequency of 8 GHz and 1M KOH activating agent. The morphological on the RAM surface shows the pore size of activated carbon on a 1M activating agent preferable than 5M and non-activated carbon. Based on the measurement result, the activated carbon of the palm shell can be used as the radar absorber material for the anechoic chamber application.