An Enhanced Model for the Analysis of Non-Uniform Multiconductor Transmission Lines Based on Scattering Theory

Classical multiconductor transmission line (MTL) theory can only model infinitely-long transmission lines whose cross sectional dimensions are very small compared to the wavelength. In this paper, an enhanced transmission line theory has been developed to model nonuniform transmission lines. The proposed method uses scattering theory to model mutual coupling between conductors, and therefore can accurately model differently-lengthed, electrically distant conductors. Four cases of simulation results for a 2-conductor transmission lines whose conductors are of different lengths and their separation is comparable to the wavelength are presented in this paper. The results obtained using the proposed approach are validated using Numerical Electromagnetic Code (NEC) that is a full-wave, thin-wire electromagnetic solver. We have compared the results both in the frequency domain and in the time domain.