运用边界形状摄动方法 (PMOBG)对类同轴线的 TEM模进行模式分析 ,得到了电位分布函数表达式 ,进而运用摄动积分法求得偏心同轴线分布电容的摄动表达式 ,并对其精度和适用范围进行了讨论 By using the method of Boundary Shape Perturbation (PMOBG), the mode analysis of the TEM-like coaxial lines is carried out. The expression of the potential distribution function is obtained. Then the perturbed integral method is used to obtain the perturbation expression of the distributed capacitance of the eccentric coaxial line. Its accuracy and scope of application are discussed