Resonantly induced transparency for metals with low angular dependence

摘要: Thin (sub skin-depth) metal layers are known to almost completely reflect radiation at microwave frequencies. It has previously been shown that this can be overcome resonance via the addition of closely spaced periodic structures on either side film. In work, we have extended original one-dimensional impedance mechanism use two-dimensional both experimentally and analytically using an equivalent circuit approach. The resulting device shows a low (<5% relative frequency shift) dependence in angle incidence polarisation. We also show same principle used transmit through thicker (∼μm) perfectly conducting film perforated with non-diffracting (short pitch) array subwavelength holes cut-off above 900 GHz showing resonant transmissivities 20–30 GHz range 40%.