降低电磁波在再入等离子体中衰减的仿真分析

Simulation Analysis of Reducing Electromagnetic Wave Attenuation Through Reentry Plasma

对电磁波在再入等离子体中的衰减特性进行了分析。在不减少辐射口面处等离子体电子总数的条件下,提出一种极化方向电子密度周期变化分布降低电磁波衰减的方法。对于电子密度均匀分布与再入过程中实际分布的等离子体模型,采用发射与接收天线,对电磁波在等离子体中的传播特性进行仿真。得到了电子密度均匀分布与周期变化时的电场分布图,分别计算了电子密度均匀分布与实际分布时的电磁波衰减,对原分布与周期变化分布时产生的电磁波衰减进行比较。仿真结果表明,极化方向电子密度的周期变化,可有效改善电磁波的传播特性,使电磁波衰减降低。

Electromagnetic wave attenuation characteristic in reentry plasma was analyzed. Based on non-decreasing total amount of plasma electron on radiation aperture,a method of reducing electromagnetic wave attenuation by changing electron density periodically along direction of polarization was presented. For electron density with uniform distribution and actual reentry experiment distribution,electromagnetic wave propagation was simulated by using transmitting and receiving antennas. Electric field intensity of electron density with uniform distribution and periodically changed distribution was simulated. The electromagnetic wave attenuation for uniform distribution and actual reentry experiment distribution was calculated,and the attenuation for primary distribution and periodically changed distribution was compared. The simulation results show that the electromagnetic wave attenuation is decreased,and the electromagnetic wave propagation characteristic is improved by changing electron density periodically along direction of polarization.