一种分析二维平面左手结构的新方法

A New Method to Analyze Planar 2-D Left-Handed Structures

本文提出了一种基于单元结构的四端口网络S参数和周期性结构的Bloch理论来分析二维平面分布参数左手结构的新方法,以及基于Bloch波数和Bloch阻抗来判断左右手特性频带的新方法.与以往的单元结构分析方法相比,本文方法有利于单元结构的灵活设计,能较好地考虑分布参数元件色散特性,能简便准确地判断出左右手特性频带,且能用于分析各向异性和有损耗结构.作为例子,我们设计了一种串联电容增强型平面左手结构,并用本文方法进行分析,清楚地得到了该结构的左右手特性频带.本文还采用时域有限差分方法(FDTD)对这种新型平面结构阵列进行模拟,在左手特性频带内得到了后向波传播特性,从而验证了本文方法的有效性.

A method based on the 4-pert S parameters of the unit cell and the Bloch theory is proposed to analyze planar 2- D Left-handed structures. The Left/Right-handed frequency bands are identified by the Bloch wave number and the Bloch impedance. Compared to the previous unit cell analysis methods, the new method is suitable for analysis of more flexible structures, can give better consideration to the distributed elements＇ dispersion, can determine the Left/Right-handed frequency bands more easily and accurately, and can be used to analyze anisotropic and lossy structures. As an example, a capacitance-enhanced Left-handed structure is designed and analyzed with the new method. FDTD simulation is also performed to illustrate the backward wave propagation in the periodic structure with infinite arrays in Left-handed frequency band. This demonstrates the effectiveness of the new method.