Ultra-broadband metamaterial absorber using slotted metal loops with multi-layers and its ECM analysis

An ultra-thin and broadband absorber which consists of periodic rings with gaps is proposed in this paper. The periodic rings are printed on the middle metallic layers in a four-layer substrate of total thickness is only 3.4mm. Simulation results, which are gotten by using FEM, show that the absorption is higher than 90% cover the frequencies range from 8.4GHz to 23.6GHz. The measurement results of the absorption agree with simulated ones very well. We also give the Equivalent Circuit Model (ECM) of the absorber structure.