Hybrid method for frequency-dependent lossy coupled transmission line characterization and modeling

This paper presents a hybrid method that combines measurements, electromagnetic (EM) numerical tools, and extrapolation techniques for accurate modeling of lossy multi-transmission lines over tens of gigahertz (GHz) ranges. The parameters of the RLGC model are made up of the frequency-dependent characteristic impedance and the propagation constant, which are de-embedded from measured scattering (S) matrices of two transmission lines of different lengths and an extrapolation technique. By combining the extracted RLGC parameters with an EM tool, the relative permittivity and loss tangent of a dielectric substrate and the effective conductivity of a conductor for considering the surface resistivity due to skin effect and surface roughness are determined accurately. Multiconductor transmission lines are simulated using tabular W-element models based on frequency-dependent RLGC parameters.