ABSTRACT
For the calculation of tensions and currents, at the beginning and the end of transmission lines (TLs), in steady-state, it is necessary to develop models that represent TLs. These models are obtained for short-length, medium-length, and long-length TLs. In practice, all real circuits are distributed parameters. But it is possible to neglect the transverse current derivation, due to the value of the current through the longitudinal elements, or the variation of the longitudinal voltage, because of the potential difference between the conductors of the circuit. The characteristic propagation parameters, which are characteristic impedance, propagation constant, attenuation constant, phase constant, and wave propagation speed, are functions of the frequency. The analysis of these parameters with frequency is relevant for the study of transient lines.
