The response of a two-wire transmission line to incident field and voltage excitation, including the effects of higher order modes

The surface currents on a two-wire transmission line induced by incident field excitations are investigated using the spectral concept. A simple solution is obtained for plane wave excitation. A solution for voltage source excitation, in which the induced current may be given, at least approximately, by means of the so-called leaky-wave concept, is considered. The influence of the electrical dimensions of the structure on the currents and the relative importance of the higher modes are examined by numerical examples.