中文摘要：

建立准确的色散介质本构模型是计算色散介质中波的散射和传播的基础,目前处理色散介质电磁问题通常采用的方法是基于某一种常见的经典模型来进行分析。而实际的色散介质往往是极其复杂的,近似为某一种常见模型对其进行分析计算是不够精确的。结合常见的3种色散介质模型（Debye、Lorentz和Drude模型）,在简单混合模型的基础上提出分段线性混合模型,并通过对异向介质参数进行拟合验证,检验了新型模型的准确性与可行性。

英文摘要：

Setting up an exact model of constitutive relation is the foundation of analyzing electromagnetic scattering and propagation in dispersive media.Nowadays,the common way for dealing with such problems is based on a certain general classical model,but it is not accurate enough to set up a general model on the basis of only one approximate model for analysis since the natural dispersive media are quite complicated.Based on the simple composite model,a piecewise linear composite model was proposed that combined the three general models（i.e.,Debye,Lorentz and Drude models）.A numerical fitting example for metamaterial verified the correctness and validity of the proposed new model.