中文摘要：

推导了计算一维时变磁化等离子体的时域有限差分（finitedifferencetimedomain，FDTD）的递推式，分析了一维情况下的时变等离子体中电磁波的频域特性，并通过选取算例，验证了该方法的准确性。对将等离子体频率按时间分为3个阶段的复杂情况进行了计算分析，通过改变时变磁化等离子体占空比，得出了时变磁化等离子体对电磁波有频率漂移和频谱展宽等规律。

英文摘要：

The finite difference time domain （FDTD） formulas for one-dimensional time varying plas ma are deduced. Characteristics of electromagnetic wave in the time-varying plasma of one-dimensional ca- ses are analyzed. The accuracy of the FDTD method is proven to be correct by the comparison of numeri- cal results and theoretical analysis. The complex issue that the plasma frequency is divided into three time-accordantly stages is also calculated by the modified method. By the comparison of electromagnetic wave in time-varying plasma with different duty cycles, the conclusions of frequency drift and spectral broadening are obtained.