ESTIMATION OF PROXIMITY EFFECT ON THE ELECTRICAL CHARACTERISTICS OF MULTI-CONDUCTOR LINES

Investigations on the effect of non-uniformity in charge distribution over the surfaces of parallel cylinders of transmission lines due to t he proximity effect on their impedance and field distribution are pres ented. Expressions for the location of points which are mutually inver se to a pair of circles representing the cross-sections of parallel cy linders and through which the equivalent filamentary line charges pass are first found. The potential function, capacitance, impedance and f ield distribution for a line consisting of a centre cylinder surrounde d by a number of grounded cylinders are found in terms of the expressi ons for the inverse points. Numerical data are presented for: a two-co nductor line of unequal radius; a three-conductor line with coplanar a xes and symmetric as well as asymmetric location of grounded conductor s; a four-conductor line with non-coplanar axes and finally, a multi-c onductor line.