等离子体的SO-FDTD算法和对电磁波反射系数的计算分析

SO-FDTD method and its application to the calculation of electromagnetic wave reflection coefficients of plasma

将一类色散介质的介电常数写成有理分式函数形式,进而导出FDTD中电位移矢量D和电场强度E之间的关系,形成SO_FDTD方法.应用该方法计算了冷等离子体平板对电磁波的反射系数,通过与解析结果的比较,验证了该算法的高效性和高精度,同时,应用SO_FDTD方法,计算了等离子体层对垂直入射电磁波的反射系数,结果表明等离子体厚度、电子密度、电子密度的分布形式和入射波频率是影响反射系数的重要因素.

The dielectric property of dispersive media is written as rational polynomial function, the relation between D and E is derived in time domain. It is named shift operator FDTD （SO-FDTD） method. The high accuracy and efficiency of this method is confirmed by computing the reflection coefficients of electromagnetic waves by a collisional plasma slab. The reflection coefficients between plasma and the atmosphere or vacuum can be calculated by using the SO-FDTD method. The result is that the reflection coefficients are affected by plasma thickness, electron numerical density, the distributing orderliness of electron density, and incidence wave frequency.