地-电离层腔体中极低频天线辐射场的数值计算

经典的球面波导模式理论给出了极低频（ELF）天线在地-电离层腔体中激励的电磁场的表达式,该表达式涉及到复阶数Legendre函数的计算,已有文献给出的渐近解析式不适用于极低频段的低端。文章基于Runge-Kutta法,建立了任意复数阶Legendre函数的数值计算方法,从而得到了电磁场的数值解。经与文献结果比较,证明了所建立的算法正确有效。

Radiation Field of the ELF Antennas in the Earth-Ionosphere Cavity

The mode solution for the extremely low frequency（ELF） vertical and horizontal dipoles in the earth-ionosphere cavity is presented in this paper.In order to calculate the complex order Legendre function appearing in the mode solution of the electromagnetic fields,the Runge-Kutta method is used.Using the method presented in this report,some examples are analyzed and the numerical results are compared with the data published in the literature.It is proved that the presented method is valid.