特种截面传输线特性阻抗计算的一种方法

本文提出用圆或椭圆图形逼近多角形边界、计及其角形外导体边界的电荷角效应影响和取截面边界尺寸上、下限几何平均值的方法,计算特种截面传输线特性阻抗,得到了矩形外导体-椭圆内导体、圆形外导体-正三角形内导体、圆形外导体-正五边形内导体、圆形外导体-正六边形内导体、椭圆外导体-矩形内导体等五种新型传输线和九种现有传输线特性阻抗的初等函数计算公式,通过计算数值与有关文献的精确值比较,证实了本文方法及其特性阻抗计算公式的准确性。 关键词：

A METHOD OF SOLVING TRANSMISSION LINES OF SPECIFIC CROSS-SECTION

A method is presented to solve the characteristic impedance of transmission lines of specific cross-section. In this method, we use the circle or ellipse to approximate polygonal boundaries, taking account of ′angular effect′ of the electric charge of polygonal outer conductor, and take geometric mean of the upper and lower bounds to the size of the cross-section. The formulae for calculating the characteristic impedance of five new transmission lines (i.e. with rectangular outer and elliptic inner, circular outer and equilateral triangular inner, circular outer and regular pentagonal inner, circular outer and regular hexagonal inner, elliptic outer and rectangular inner cross sections respectively and nine existing transmission lines are obtained, all expressed in terms of elementary functions. The accuracy of the expressions is confirmed by comparing the numerical values obtained with exact values of same relative problems in the literatures.