Design and Analysis of a flexible and optically transparent of Multi-Band Absorber with Polarization Insensitivity for conformal applications

Abstract

This study presents the design and analysis of a multi-band, optically transparent metamaterial absorber (MA) based on a 5×5 array of unit cells, bent by 90 degrees to investigate its electromagnetic response over a frequency range of 0 to 25 GHz. The absorber is constructed using indium tin oxide (ITO) and polyethylene terephthalate (PET) films on a polyvinyl chloride (PVC) substrate, achieving high absorption efficiency across multiple frequency bands. Characteristic Mode Analysis (CMA) is applied to optimize the resonant behavior of cross-shaped and ring-shaped resonators, while accounting for the effects of bending on surface current distribution and modal coupling. Surface current distribution is thoroughly analyzed for the bent structure, revealing significant changes in resonant behavior compared to the flat configuration. The absorption characteristics are compared across different incident angles (0°, 15°, 30°, and 45°), with the results showing shifts in resonant frequency and absorption efficiency. Although absorption remains high at normal incidence, predictable degradation is observed at higher angles. The study provides key insights into the design of flexible, broadband absorbers for applications requiring transparency and angular stability, such as electromagnetic interference (EMI) shielding and stealth technology. This MA offers a promising solution for optoelectronic devices, with potential for further optimization to improve angular performance.