Ultra-Wideband Multi-Layers Absorber Based on Equivalent Circuit Model

In this work, an ultra-wideband multi-layers absorber composed of five-layers indium tin oxide (ITO) resistance films is presented based on the equivalent circuit model (ECM). Square patch and square loop are selected as the lossy patterns due to their simplicity of construction and better electromagnetic performance. The absorption of electromagnetic waves can be enhanced by cascading ITO with different sizes of square pieces and square ring patterns. Further, the proposed cascade structure is analyzed by ECM. The reflection coefficients of the ultra-wideband absorber is lower than -10dB from 1.14 to 29.26 GHz (the fractional bandwidth (FBW) of absorption is 185%). Finally, the theoretical analysis with ECM and the simulation results are in good agreement.