Design of Carbon Black Reinforced Composite RAM Using Mixing Model Assisted-Methodology

The microstructure of the composite material is a crucial factor in designing a radar absorbing material (RAM). To design and utilize these composite materials effectively as RAMs, accurately predicting their electromagnetic properties is essential. This is typically accomplished through the use of mixing models, which can forecast the behavior of composite materials. In this article, we employ the Maxwell-Garnett (MG) model, a popular mixing model, to model carbon black (CB) reinforced composites. We address the challenges associated with modeling CB composites using the MG model. We investigate two different manufacturing processes, namely: 1) mechanical stirring and 2) homogenizing. We use the best fit between measured permittivity and computed permittivity from the MG model to determine the electrical conductivity and aspect ratio of CB embedded in epoxy resin and verify our model through experimentation. Our findings indicate that both manufacturing processes can be simulated using the MG model and a constant value of conductivity and aspect ratio characterizes a given manufacturing process in the 8–12.5-GHz frequency range. To further test the effectiveness of our model in RAM design, we apply it to predict reflection loss in the 8-12.5-GHz range and experimentally verify the results. Finally, we utilize the mixing model in an analytical approach to develop a multilayer broadband RAM.