Multilayer microwave absorber based on CaCu3Ti4O12, Mn0.6Zn0.4Fe2O4, and carbonyl iron

Multilayer microwave absorbers are designed for applications requiring broadband electromagnetic (EM) wave absorption. This configuration typically employs two types of layers: matching and attenuation layers, selected based on their impedance (Z) and position. In this work, composite layers of CaCu3Ti4O12 (CCTO), carbonyl iron (CI), and Mn0.6Zn0.4Fe2O4 (ferrite) were used to simulate the EM absorption properties of a double-layer configuration using Python. Computational tools can expedite absorber development by identifying optimal layer configurations to enhance the attenuated frequency range. The morphology and structure of the fillers were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Samples were fabricated with 60 wt% of each filler in a polymer matrix, with thicknesses ranging from 1 to 3 mm. From 24 simulated combinations, 5 exhibited EM absorption properties in the Ku band. The best broadband absorption was achieved with a 3 mm thick layer 2 (t2) and using the real permittivity of the CCTO layer for layer 1 (epsilon'). The sample with a 3 mm CI layer and a 1 mm CCTO layer demonstrated the minimum reflection loss (RL) of -30.17 dB and a bandwidth of 2.88 GHz (from 15.12 to 18 GHz).