等离子体天线色散关系和辐射场数值计算

研究了电磁波沿轴向对称柱形等离子体天线传播的特性、色散关系及辐射方向图、增益等天线参数.通过对腔体材料介电系数、内外半径、等离子体密度、碰撞频率等参数的分析，结果表明要减小波沿等离子体天线传播的衰减，应当增加等离子体密度，减小碰撞频率，增加等离子体半径，减小腔体厚度，采用介电系数较小的材料.计算了在不同参数条件下，等离子体天线的辐射方向图、增益的变化，这些结果对于等离子体天线的设计很有参考价值. 关键词： 等离子体天线 色散关系 增益 辐射方向图

Calculation of dispersion relation and radiation pattern of plasma antenna

We investigated some important plasma antenna parameters, such as the transmission characteristics of a microwave propagating along the cylindrical symmetric plasma antenna, dispersion relations, radiation pattern and gain. By analyzing the dielectric constant of the tube material, the outer and inner radius, the density of the plasma and the collision frequency, we found that to minimize the attenuation of wave propagation along the plasma antenna, one should increase the density of the plasma, decrease the collision frequency, increase the radius of the plasma, increase the thickness of tube,and decrease the dielectric constant. We also calculated the radiation pattern of the plasma antenna and the change of gain under different conditions. These results are useful for the design of plasma antenna.