This method is using two times conformal transformation method and mirror theory to calculate the characteristic impedance. 这种方法是采用两次保角变换结合同轴线特性阻抗公式进行特性阻抗计算。
Classical complex variable method is followed, but a new conformal mapping formula is proposed so that the exterior part of the parabolic crack is mapped into a unit circle. 采用了传统的复变函数保角映射法，给出了一个新的保角变换公式，从而将抛物线曲裂纹外的区域映射到一个复平面的单位圆内。
