Dielectric Characterization of Microwave Absorbing and EMI Shielding Structures Optimized Through Firefly Algorithm

Abstract

This study presents a comprehensive investigation into the dielectric characterization of structures designed for optimal microwave absorption and electromagnetic interference (EMI) shielding, employing the innovative firefly algorithm (FFA) for optimization. The proposed structures leverage advanced polyaniline (PANI)based conducting polymer and titanium dioxide (TiO2) composites with tailored dielectric properties, systematically tuned through FFA to enhance their performance. This research aims to provide a deeper understanding of the dielectric characteristics crucial for effective microwave absorption and EMI shielding applications. The experimental methodology involves fabricating and characterizing the designed structures across a range of frequencies and assessing parameters such as complex permittivity and loss tangent. The obtained results are analyzed to elucidate the impact of the optimized structures on microwave absorption efficiency and EMI shielding effectiveness (SE). Following a thorough investigation of the composite samples, the finest dual-layer sample offers the lowest reflection coefficient (RC) of −35 dB at the resonance frequency of 12.1 GHz. In addition, by achieving an optimal thickness of merely 1.9 mm, a maximum absorption bandwidth of 2.2 GHz (10.2–12.4 GHz) is attained. Furthermore, the utilization of silver yielded the highest SE of 83 dB across the entire band as estimated by FFA. The outcomes of this research not only contribute to the fundamental understanding of dielectric properties in microwave absorbing and EMI shielding structures but also offer a practical framework for employing optimization algorithms in the development of advanced materials for electromagnetic (EM) applications. © 2024 IEEE.