Tunable triple-band millimeter-wave absorbing metasurface based on nematic liquid crystal

• Published in: AIP advances Vol. 12; no. 1; pp. 015127 - 015127-6
• Main Authors: Wang, Qiang, Liu, Yuan Ke, Wang, Gui Chen, Jiang, Wei Xiang, Cui, Tie Jun
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 01.01.2022; AIP Publishing LLC
• Subjects: Absorption; Bias; Circuits; Electric potential; Liquid crystals; Mathematical models; Metasurfaces; Millimeter waves; Nematic crystals; Red shift; Resonant frequencies; Voltage
• ISSN: 2158-3226; 2158-3226
• DOI: 10.1063/5.0075606

We propose and design a tunable triple-band millimeter-wave absorbing metasurface based on nematic liquid crystal (NLC). Numerical results based on both effective circuit model and full-wave simulations verify the triple-band absorption property. All triple absorption peaks can be shifted by changing the bias voltage applied to the nematic liquid crystal. We fabricate and measure a triple-band absorbing metasurface sample, which covers 100 × 100 mm2 and is composed of 20 × 20 unit cells. In experiments, when no bias voltage is applied to the NLC layer, the resonant frequencies of the absorbing metasurface are 25.4, 28.7, and 32.8 GHz, respectively. When a 5-V bias voltage is applied, all the absorbing peaks redshift, and a frequency tunability range of 9.5%, 9.1%, and 8.58% is observed in three resonant frequencies, respectively. The experimental results are in good agreement with the numerical simulations. The proposed tunable absorbing metasurface provides a way forward for the realization of tunable millimeter-wave metasurface devices that can be applied in multi-band detection and imaging.