Robust stability characterizations of active metamaterials with non-Foster loads
Robust stability characterizations of active metamaterials with non-Foster loads
复制标题
非福斯特负载活性超材料的鲁棒稳定性表征
DOI：
10.1088/1674-1056/27/2/028102
复制
发表时间：
2018
影响因子：
1.7
通讯作者：
Sun Yong-Zhi
中科院分区：
文献类型：
--
作者：
Fan Yi-Feng;Sun Yong-Zhi
与非福斯特元素相结合的有源超材料被认为是克服被动超材料固有局限性，从而实现宽带或增益超材料的手段之一。然而，现实中的活性超材料，特别是非Foster负载介质，将面临不稳定的可能性的挑战。此外，它们通常表现为时变且处于非定常状态，这导致在考虑系统模型不确定性的情况下，需要一种稳定性方法来处理稳定性问题。在本文中，我们提出了一种基于导纳的稳定性方法来设计一种非Foster负载的超材料，以确保鲁棒稳定性。首先，在比较不同稳定性判据的基础上，介绍了该稳定性方法的原理。在等效系统模型的基础上，利用稳定性刻画给出了设计指标，以实现具有鲁棒稳定性的活性异质材料。最后，将其应用于非Foster加载的有源超材料环阵的实际设计中。通过在非福斯特电路(NFC)中引入扰动，在设计过程中考虑了最坏情况下的模型不确定性，验证了所提方法的可靠性。该方法也可应用于其他活性超材料的真实感设计。
Active metamaterials incorporating with non-Foster elements have been considered as one of the means of overcoming inherent limitations of the passive counterparts, thus achieving broadband or gain metamaterials. However, realistic active metamaterials, especially non-Foster loaded medium, would face the challenge of the possibility of instability. Moreover, they normally appear to be time-variant and in unsteady states, which leads to the necessity of a stability method to cope with the stability issue considering the system model uncertainty. In this paper, we propose an immittance-based stability method to design a non-Foster loaded metamaterial ensuring robust stability. First, the principle of this stability method is introduced after comparing different stability criteria. Based on the equivalent system model, the stability characterization is used to give the design specifications to achieve an active metamaterial with robust stability. Finally, it is applied to the practical design of active metamaterial with non-Foster loaded loop arrays. By introducing the disturbance into the non- Foster circuit (NFC), the worst-case model uncertainty is considered during the design, and the reliability of our proposed method is verified. This method can also be applied to other realistic design of active metamaterials.