Transmission Lines Modeling Approach Based on the Approximation of Pade

Abstract

This paper is devoted to the modeling of transmission lines in the frequency and time domain. A Multiconductor Transmission Lines (MTL) modeling approach based on Pade approximations is proposed. The main objective is to model the transmission lines with or without shielding taking into account the variable losses characterized by linear parameters dependent on the frequency. In addition, this approach is compared to the other two modeling methods namely the traditional cascade model and Branin model. In a first step, we determine the relative admittance matrix for the line as a function of the linear parameters and the Pade polynomials. This matrix is associated with a macro-model called Pade. This macro-model is then implemented in the Emcap2000-Esacap circuit simulator using the Modified Nodal Analysis method (MNA). In order to validate our algorithm in the case of lines with constant losses, examples of applications in the time and frequency domain are presented. The first example presents a single transmission line that will be analyzed in the time and frequency domain by three different approaches namely the cascade model, Branin model and the pade approximation method. The second example deals with a multi-wire line of two conductors and the third example presents a line of three coupled conductors that will be analyzed by the Branin and the Pade approximation methods. The performed simulations and obtained results are reported and analyzed.