Wideband E-shaped element of THz metamaterial absorber and equivalent-circuit analysis

The wideband absorbance of the absorber has been realized by modifying geometrical shape of conventional rectangular patch in single periodic cell. The increase of relative bandwidth of this new absorptive cell structure with E-shaped patch can reach and exceed 100% with respect to the centre frequency comparing with rectangular patch. The new structure of absorber exciting a new broadband resonant modes results in the bandwidth expanding. The work presented here provides an efficient method to decrease the number of elements and layers of multi-layer metamaterial absorber compared to conventional element structures used previously. A simple equivalent circuit method has also been presented to understand the mechanism of achieving an impedance bandwidth as well as.