Design and development of rice husk, coconut husk, and charcoal powder based microwave absorber

Abstract A novel composite agricultural residues-based microwave absorber is proposed to design and fabricate to achieve minimum electromagnetic pollution. In the frequency range of 1–20 GHz, this study intends to fabricate a lightweight, inexpensive, and environmentally friendly microwave absorber. The unique green composite made of rice husk, coconut husk, and charcoal powder was used to create the samples with various compositions. The dielectric characteristics and the samples’ reflective qualities are measured using the open-ended coaxial probe technique. Additionally, CST MWS 3D EM simulation software is used to create the suggested structure. Additionally, the experimental outcome of the open-ended coaxial measuring approach is contrasted with the modelling outcome. The maximum return loss of -37.27 dB at 10.6236 GHz and average return loss of -18.01 dB, or more than 98% absorption rate, are provided by the absorber with greater charcoal content (11.11 wt%). The outstanding agreement between the simulation and practical findings validates the universality of the simulation.