CAPACITANCE OF TRANSMISSION-LINE OF PARALLEL CYLINDERS IN THE PRESENCE OF DIELECTRIC COATING

The paper presents a method for the evaluation of variation of capacit ance of a dielectric coated two-wire line of parallel cylinders, each of unit radius with a change in thickness of the dielectric along the radial direction. A conformal transformation is used to transform the conductor and dielectric boundaries to appropriate contours extending over a fixed region along the imaginary axis in the transformed plane, Approximating the continuous curve obtained through transformation of dielectric boundaries by a very large number of discrete steps, the e xpression for the capacitance is derived in the form of a definite int egral, Numerical data on capacitance as a function of width of the die lectric in the absence and presence of a conducting ground plane are p resented.