Numerical analysis of complex impedance and microwave absorption of metamaterials composed of split cut wires on grounded dielectric substrate

Abstract

The microwave absorption of metamaterials composed of split cut wire (SCW) on grounded dielectric substrate has been investigated on the basis of equivalent transmission line circuit. S-parameters (S11 and S21) and input impedance are numerically simulated with variations of the thickness and dielectric loss of the substrate and the geometry of the SCW. Magnetic resonance resulting from antiparallel currents between SCW and ground plane was observed at the frequency of minimum reflection loss. The simulated resonance frequency and reflection loss can be explained well on the basis of the circuit theory of an LC resonator. Analysis of the input impedance of the high impedance surface has shown that perfect absorption can be obtained at the optimized impedance-matching condition, which is dependent on SCW width, thickness and the dielectric loss of the substrate. Better insight into the absorption mechanism of metamaterial absorbers can be attained through the parametric analysis on complex impedance of SCW and its relationship with reflection loss.