Characteristic impedance of two special forms of transmission line

Abstract
Two specialised forms of transmission line which have been used in the past are, firstly, one in which the two conductors are opposing arcs of a circle and, secondly, one consisting of a thin strip in a rectangular outer tube. Exact theoretical solutions for the characteristic impedances have been found for infinitely thin (perfect) conductors, and corrections are given which show the effect of finite thickness in the conductors.