通道参数对MPCA传播特性的影响分析

Analysis of Channel Parameter on MPCA Propagation Properties

该文针对现有高功率微波武器辐射天线的不足,提出了将磁化等离子体通道用作电磁脉冲辐射天线的思想——磁化等离子体通道天线(MPCA),分析了MPCA周围为有耗气体媒质时MPCA所传播的一般模式。简单阐述了MPCA的具体实现方法,根据MPCA的工作原理,建立了MPCA的几何模型,导出了广义柱坐标系下磁化等离子体中纵向场所满足的波动方程及纵-横的关系,利用边界条件导出了MPCA严格的特征方程。重点讨论了MPCA的传播常数随等离子体通道参数(等离子体频率和通道半径)的变化。结果表明,强磁场时等离子体频率对天线衰减常数影响增大,且有一极值出现。

In order to cover the shortage of the current antenna for high power microwave weapon, the idea of a magnetized plasma channel used as antenna for radiating electromagnetic pulse is proposed. The normal modes of Magnetized Plasma Channel Antenna （MPCA） in lossy gas are analyzed. The concrete realization method of MPCA is simply described. The geometric-model of MPCA is created based on the operating principle of the antenna. The wave equations for the longitudinal electromagnetic fields and the relations between the transverse electromagnetic fields and longitudinal ones of magnetized plasma in generalized cylindrical coordinate are given. The strict characteristic equation of MPCA is deduced by using the boundary conditions of electromagnetic fields. Discussion is stressed on the variations of propagation constants with plasma channel parameters （plasma frequency and channel radius）. The analysis shows that the influence of plasma frequency on the attenuation constant of MPCA is increasing, and an extremum point is appeared.