Investigation on Fractional Bandwidth Enhancement of a Resonant Absorber

Limitation of the absorption band is an inherent problem in the resonant absorbers. An investigation carried out to address this problem is presented in this magazine. Initially, we have designed a resonant absorber using the conventional metal-insulator-metal configuration, which provides a narrow fractional bandwidth (FBW) of 3.4%. Then the FBW of the absorber is increased up to 28.4% by modifying the conventional configuration while maintaining the same resonant frequency for both absorbers. Generally, it is observed that the reflection coefficient of the absorber increases with the increase in its bandwidth. However, the proposed absorber increases the FBW as well as reduces the reflection coefficient simultaneously and achieves superior performance than the conventional resonant absorber. In addition, the proposed absorber is compact, thin, polarization-insensitive, and angularly stable.