On the evaluation of TL mode currents along transmission lines of finite length

In this paper, we derive a general equation describing the TL (transmission line) mode currents at any position along a uniform two-wire transmission line and give the solution expression excited by an incident plane wave. We also simplify the expressions for the per unit length distributed parameters and point out the application conditions. The derived equations are tested against numerical results obtained using the electromagnetic field analysis software FEKO, and reasonably good agreements are found. And the simplified expressions for the per unit length distributed parameters also perform well.