海伦方法分析偶极子天线的频率阻抗特性-电阻随频率的变化，电抗随频率的变化-Helen analyze the frequency dipole antenna impedance- resistance changes with frequency, the change of reactance with frequency

Hallen积分方程求线天线表面电流分布，方向图及辐射阻抗-Hallen Integral Equation for antenna surface current distribution, radiation pattern and radiation resistance