中文摘要：

本文运用格林函数法分析金属线栅在太赫兹（THz）波段的散射特性，研究金属线栅的衍射效应对其传输特性的影响。研究结果表明，在零级衍射区入射电磁波的透过振幅随a/λ的增大单调增加，在零级衍射极限处透过振幅达到最大值。过渡区的临界频率处，由于衍射效应的加强，出现入射电磁波透过曲线的振荡。衍射区受到衍射效应的影响入射电磁波透射振幅曲线总体下降，并随a/λ的增大单调减少。与微波传输线方法相比，该方法摆脱了入射电磁波的波长需大于线栅常数且要求线栅的厚度远远小于金属线的宽度的限制，能准确的分析系统的电磁场的分布特性，更具普适性。

英文摘要：

The present paper utilizes the‘Green function method’ to analyze the scattering properties of the metal wire grating in the THz band, and further to study the influence of the diffraction on the transfer characteristic of the metal wire grating. Results prove that the transmission amplitude of the incident electromagnetic wave is increasing monotonously with the enlargement of the value of a/λ, and it arrives at the maximum in the zero-order diffraction limit. Due to the strengthened effect of diffraction, transmission curves of the incident electromagnetic wave show oscillation in the critical frequency transition region. Due to the diffraction effect, the transmission amplitude of the incident electromagnetic wave demonstrates an overall decline in the diffraction zone, and it is decreasing monotonously with the enlargement in the value of a/λ. Compared with microwave transmission line method, this method can aliminate the restriction that the wavelength of the incident electromagnetic wave must be greater than the wire grating constant, and the thickness of wire grating must be far less than the metal line width. This method could be used to analyze the distribution of the electromagnetic properties of the system accurately;and it will be a generally suitable one.