Simulation models of a dissipative transmission line above a lossy ground for a wide-frequency range. I. Single conductor configuration

The simulation model of a single conductor dissipative line above a lossy ground, based on the exact formulation of the Maxwell equations, is proposed for a wide frequency range. The transmission-line (TL) and fast-wave (FW) propagation constants of the line are computed by solving the modal equation coming from the continuity of the tangential component of the electric field at the air-wire interface. Three different expressions of the distributed line impedance and admittance are suggested with reference to different definitions of the line voltage. Moreover, logarithmic approximations of the Sommerfeld integrals are proposed in order to obtain an easy-to-implement formulation of the simulation models for use in computer codes. Comparisons between the proposed models and the Carson (1926) approach are carried out with reference to a single conductor line above a lossy earth, considering different values of the line geometrical parameters and ground conductivity and permittivity.