A Circuit-Based Model for the Interpretation of Perfect Metamaterial Absorbers
A Circuit-Based Model for the Interpretation of Perfect Metamaterial Absorbers
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DOI：
10.1109/tap.2012.2227923
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发表时间：
2013-03-01
影响因子：
5.7
通讯作者：
Manara, Giuliano
中科院分区：
文献类型：
--
作者：
Costa, Filippo;Genovesi, Simone;Manara, Giuliano
利用高效传输线模型，研究了一种常用的吸收结构，通常被称为完美超材料吸收器，它包括薄的低损耗接地衬底上的金属周期性图案。这种方法可以推导出简单可靠的封闭公式来描述亚波长结构的吸收机理。明确推导了输入阻抗实部的解析形式，以解释为什么衬底的适度损耗足以实现与自由空间的匹配，即完美的吸收。讨论了各组成参数对调谐工作频率和调整吸收带宽的影响。它还表明，选择高电容耦合元件可以获得最大可能的带宽，而使用低电容元件（如交叉阵列）可以实现高频选择设计。最后对吸波结构的角稳定性进行了研究。
A popular absorbing structure, often referred to as Perfect Metamaterial Absorber, comprising metallic periodic pattern over a thin low-loss grounded substrate is studied by resorting to an efficient transmission line model. This approach allows the derivation of simple and reliable closed formulas describing the absorption mechanism of the subwavelength structure. The analytic form of the real part of the input impedance is explicitly derived in order to explain why moderate losses of the substrate is sufficient to achieve matching with free space, that is, perfect absorption. The effect of the constituent parameters for tuning the working frequency and tailoring the absorption bandwidth is addressed. It is also shown that the choice of highly capacitive coupled elements allows obtaining the largest possible bandwidth whereas a highly frequency selective design is achieved with low capacitive elements like a cross array. Finally, the angular stability of the absorbing structure is investigated.