A Fano-Reflection Metafilm Composed of Metamaterial-Lined Discs

This work presents a compact metafilm, which provides frequency-selective reflection and is based on subwavelength metallic discs lined using μ -negative and near-zero (MNNZ) metamaterial liners. It is shown that such particles undergo resonance at sizes of λ/7 or smaller and exhibit interesting transmission/reflection behaviour. It is further demonstrated that when an array of these resonators is illuminated using a normally or obliquely incident plane wave, a Fano-shape reflection profile is obtained, exhibiting a high degree of reflection at resonance followed by strong transmission. These resonators may be closely packed since the resonance mechanism does not rely on diffraction effects. We present simulation data and experimental results demonstrating 98.4% (18-dB) decreased transmission at resonance using a polarization-insensitive compact metafilm measuring 1.7λ by 2.3λ, as well as near-transparency at other frequencies. This novel unit cell provides compact solutions for applications such as switching owing to its miniaturized size and Fano-shape reflection response.