Tunable terahertz metamaterial wideband absorber with liquid crystal

In this paper, a tunable metamaterial absorber (MA) based on liquid crystal (LC) with wideband absorption is presented. The design and absorption principle of the absorber is introduced, and the simulation analysis is conducted. The results show that the center resonant frequency of the proposed absorber is 130.0 GHz without a bias voltage. When the bias voltage increases to saturation, the center resonant frequency of the absorber is tuned to 119.9 GHz, with a frequency tunability of 7.8%. Moreover, the tunable absorber exhibits wideband absorption characteristics and maintains absorption above 90% in the frequency range of 127.7 GHz to 132.3 GHz with no bias voltage, with a relative absorption bandwidth of 3.5%. While under the saturation voltage, absorption greater than 90% can be achieved from 117.9 to 121.8 GHz, with a relative absorption bandwidth of 3.3%. The wideband absorption effect of the proposed LC-based tunable MA makes it a promising candidate for applications such as electromagnetic shielding and stealth.