An Ultrawideband Metamaterial Absorber Based on Lumped Resistor

In this paper, we proposed an ultrawideband metamaterial absorber based on a lossy stepped impedance resonator (SIR). The printed metallic patterns provide LC resonance for metamaterial absorbers. The lumped resistor is loaded for the lossy characteristics of the SIR, thereby simultaneously enabling ultrawideband absorption intensity. Moreover, the equivalent circuit model (ECM) of the lossy-SIR-based absorber is developed to explain the operating principle and facilitate our discussion on the parametric effects. The simulated effective absorption bandwidth is 4.8–17.9 GHz (115.4%) for transverse electric (TE) polarization, and 4.82–17.8GHz (114.7%) for transverse magnetic (TM) polarization. The proposed absorber has the unique advantages of ultrawideband absorption, which is of great significance for application in antenna decoupling.