Six-band polarization-insensitive perfect metamaterial absorber using L-shaped resonators

In this paper, we propose a perfect metamaterial absorber (PMA) composed of four groups of L-shaped resonators in the top layer, a dielectric spacer and a metallic back plate. Both simulation and experiment show that the PMA has six distinctive absorption peaks at 5.55 GHz, 6.51 GHz, 7.71 GHz, 9.45 GHz, 11.31 GHz and 13.11 GHz with high absorbance. The loss properties and field distributions are studied to demonstrate the absorption mechanism. This PMA is polarization insensitive over wide angles of incident waves for both transverse electric (TE) and transverse magnetic (TM) modes. Moreover, the absorption characteristics including the resonant frequency, the amplitude and the quality factor of the absorption peaks can be effectively tuned by changing the structural parameters, thus enabling potential applications such as stealth, spectrum identification and sensing.