金属螺旋的旋波特性研究

采用细线近似对金属螺旋线的电磁散射作距量法数值研究，对于具有镜象对称特性的右旋和左旋金属螺旋，计算了不同尺寸，不同电磁波投射方向下的感应电流和散射场幅值，计算结果表明，由它们产生的感应散射场同样具有镜象对称性，计算得到的前向和背向散射场显示不同旋向的螺旋对散射场的极化产生相反的旋转。

Research on Chirality of Metallic Helix

The induced current distribution on the metallic helix is determined by the method of moments under the approximation of fine wire. The current is expanded in segmented sine basis functions and the point matching technique is used. From the current distributions on the helixes the far-zone scattered fields are calculated for different size and incident field. The current distributions of the right and left handed helixes appear chirality, so the far-zone scattered fields appear chirality too. The rotations of polarization of far-zone scattered fields with the incident field from the two kinds of helix are same in amplitude and opposite in direction. It is clear that the chirality of the composite chiral media in which the metallic helixes are embeded is caused by the chirality of the single helix. The numerical results of the effective permittivity, permeability and chirality admittance of the composite chiral medium will be presented at following paper.