垂直电偶极子在负折射媒质涂覆基底上产生的场

Electromagnetic field generated by a vertical electric dipole in a negative-index media coating a planar perfect conductor

研究了垂直电偶极子在负折射媒质涂覆的理想导电基底上产生的电磁场,获得了场分量的解析表达式。分析和计算结果表明,电偶极子激发的电磁场可分解为直达波、反射波、侧面波和表面波。其中表面波在负折射媒质表面传播的波数介于空气层和介质层中传播波数之间,其幅度在距离向按波的几何扩散规律衰减,在垂直于介质层方向则以正弦或余弦规律变化。由于存在三种传播波数的波,它们共同作用形成的总场将发生复杂的干涉现象。

In this paper, the electromagnetic field produced by a vertical electric dipole in a negative-index media coating a planar perfect conductor is discussed, and the explicit formulas of the field which are convenient for calculation are derived. Analytical and calculation results show that the electromagnetic field in the negative-index-media is consisted of the direct wave, reflected wave, lateral wave and surface wave. The wave-number of the surface wave is between the wave-number in the air and that in the negative-index media. The amplitude of the surface wave for the lossless media attenuates as geometry divergence factor in the radial direction, while it varies with cosine or sine function in the vertical direction. Because of the hybrid effects of the lateral wave and surface wave, the total fields appear the complicated interference.