Opt Express. 2022 Dec 5;30(25):45883-45894. doi: 10.1364/OE.478254.
In this paper, we propose an interesting thermally tunable broadband metamaterial absorber based on ionic liquids at the microwave band, which has distinct modulation characteristics in different frequency bands. Numerical simulation results show that the absorption decreases with the increase of temperature in the low-frequency band from 2-10GHz, which decreases to 60% at 100 °C. Meanwhile, the absorption increases with the increase in temperature in the high-frequency band from 25GHz to 48GHz. In addition, the absorber still has good broadband absorption without the metal substrate, and the absorption reaches more than 80% in the frequency band of 13.96-34.10GHz. As an all-dielectric metamaterial absorber, its absorption increases with the increase in temperature, which reaches more than 90% in the range of 20.44-50GHz at 100 °C. At last, the designed metamaterial absorbers have been fabricated based on ionic liquids, and experimental results are presented to demonstrate the validity of the proposed structure. Furthermore, the simple design and wide frequency tuning range of the absorbers can promise a great potential application in sensors, detection, and frequency-selective thermal emitters.
本文提出了一种基于离子液体的微波频段有趣的热可调谐宽带超材料吸收体，它在不同频段具有明显的调制特性。数值模拟结果表明，在 2-10GHz 的低频段，吸收随温度的升高而降低，在 100°C 时降低到 60%。同时，在 25GHz 到 48GHz 的高频段，吸收随温度的升高而增加。此外，吸收体在没有金属衬底的情况下仍具有良好的宽带吸收，在 13.96-34.10GHz 的频段吸收达到 80%以上。作为一种全电介质超材料吸收体，其吸收随温度的升高而增加，在 100°C 时，在 20.44-50GHz 的范围内超过 90%。最后，基于离子液体设计并制造了所提出的超材料吸收体，并给出了实验结果，以验证所提出结构的有效性。此外，吸收体的简单设计和宽频率调谐范围可保证其在传感器、检测和频率选择热发射器等方面有很好的应用前景。
