雙週期表面阻抗散射特性研究

Abstract

我們利用阻抗表面( impedance surface )的觀念代替雙週期性結構( doubly periodic structure )來描述問題 , 經由多層介質間邊界條件的運算，可得到, 經此阻抗表面散射的波( scattering )可以用嚴格的公式來表示成三維之邊界值問題( three-dimension boundary-value problem )，包括橫向極化電波( transverse electric polarized wave )與橫向及極化磁波( transverse magnetic polarized wave )之間的耦合現象，而當某些反射波在橫向( transverse) 的傳播常數和此阻抗表面的傳播常數相等時, 反射波將會被吸收而成表面波(surface wave), 最後利用數值運算的結果來解釋結構的物理現象且和理論方面的配合。

We use an impedance surface here to substitute an doubly periodic structure. The scattering of waves by this impedance surface can formulated as an exact three-dimensional boundary-value problem, and the scattering characteristics of such a structure are rigorously analyzed in terms of the complete set of both TE- and TM-polarized plane waves in the uniform medium. When the transverse propagation constants of the mnth space harmonics are equal to the propagation constant of the impedance surface, it will be guided and become surface wave. Extensive numerical results are given to illustrate physical phenomena associated with the structure.