EFFECT OF DIELECTRIC SUPPORT ON THE INNER CONDUCTOR OF ECCENTRIC COAXIAL LINE

This paper presents a method for the evaluation of the effect of the d ielectric support between the inner and the outer conductors of eccent ric coaxial line, Two different conformal mappings are used to obtain two different approximate formulas for the evaluation of the capacitan ce of this structure. First, a cotangent hyperbolic transformation is used, which transforms the conductor boundaries to parallel straight l ines, and the circle surrounding the dielectric support to a curved co ntour, The same structure is also analyzed using a bilinear transforma tion expressed in terms of mutually inverse points followed by a logar ithmic transformation, In each ease, an expression for the capacitance is found by replacing the continuous curve representing the dielectri c boundary by a number of infinitesimally smalt discrete steps. A comp arison of numerical data obtained by the two methods is presented.