Huang Yongjun, Wen Guangjun, Zhu Weiren, Li Jian, Si Li-Ming, Premaratne Malin
Opt Express. 2014 Jun 30;22(13):16408-17. doi: 10.1364/OE.22.016408.
We synthesize and systematically characterize a novel type of magnetically tunable metamaterial absorber (MA) by integrating ferrite as a substrate or superstrate into a conventional passive MA. The nearly perfect absorption and tunability of this device is studied both numerically and experimentally within X-band (8-12 GHz) in a rectangular waveguide setup. Our measurements clearly show that the resonant frequency of the MA can be shifted across a wide frequency band by continuous adjustment of a magnetic field acting on the ferrite. Moreover, the effects of substrate/superstrate's thickness on the MA's tunability are discussed. The insight gained from the generic analysis enabled us to design an optimized tunable MA with relative frequency tuning range as larger as 11.5% while keeping the absorptivity higher than 98.5%. Our results pave a path towards applications with tunable devices, such as selective thermal emitters, sensors, and bolometers.
我们通过将铁氧体作为衬底或覆盖层集成到传统的无源超材料吸波器（MA）中，合成并系统地表征了一种新型的磁可调超材料吸波器。在矩形波导装置中，在X波段（8 - 12GHz）内对该器件的近乎完美的吸收和可调性进行了数值和实验研究。我们的测量结果清楚地表明，通过连续调节作用在铁氧体上的磁场，MA的谐振频率可以在很宽的频带内移动。此外，还讨论了衬底/覆盖层厚度对MA可调性的影响。从通用分析中获得的见解使我们能够设计出一种优化的可调MA，其相对频率调谐范围高达11.5%，同时保持吸收率高于98.5%。我们的结果为可调器件的应用铺平了道路，如选择性热发射器、传感器和测辐射热计。
