Reverse Design of a Sandwich Microwave Broadband Metamaterial Absorber Based on Resistive Film-PMI-Copper

In response to the current issues of narrow bandwidth and low design efficiency in absorbing structures, a reverse design study of broadband metamaterial absorbers is conducted. Utilizing a MATLAB-CST co-simulation approach, particle swarm optimization (PSO) is employed to search for parameter combinations within the design space that satisfy target requirements, thus achieving an efficient automated design method for a metamaterial absorber based on PSO. A parametric model of the metamaterial absorber is constructed using nested patterns of the Vicsek fractal and rings, with the use of resistive film to expand the absorption bandwidth. Combining the reverse design method based on PSO, a metamaterial absorber capable of effectively absorbing electromagnetic waves in the frequency range of 3–10 GHz is designed. Qualitative analysis of the absorbing mechanism of the designed metamaterial absorber is performed by examining the surface current and energy loss density distributions at resonance frequencies, revealing that the absorbing effect of this absorber structure is induced by electromagnetic wave-excited electric resonances. A simplified multiple reflection interference theory model is employed to quantitatively analyze the absorption mechanism of the designed metamaterial absorber. The performance of the designed metamaterial absorber sample is measured using the arch method, and the measurement results are found to be consistent with the simulation results. The designed metamaterial absorber can be applied to radar stealth design for military targets such as ships, demonstrating good generality and engineering application value in research methodology and approach.