摘要

We present a simple method for significantly broadening the bandwidth of a metamaterial absorber formed using only a low-conductivity alloy ring and an alloy ground plane separated by a dielectric layer. The >80% relative absorption bandwidth of the device is improved to 101.2%, which is much higher than previously reported values. The absorption mechanism for the broadband alloy absorber involves the overlapping of two different resonance frequencies. In particular, the electromagnetic energy is entirely dissipated in the alloy layer, which makes it insensitive to the loss of the dielectric layer and widens the range of choices for potential dielectric materials.