PCB conductor surface roughness as a layer with effective material parameters

A model to substitute conductor surface roughness in printed circuit boards by a layer with an effective material (lossy dielectric) is proposed and tested using the 2D finite-element method (FEM) electromagnetics numerical simulations. The results of numerical modeling of a multilayered structure corresponding to a stripline transmission line with substituted roughness are compared with the experimental results obtained on a TRL-calibrated test vehicle with significant roughness on conductors made of a standard (STD)-roughness copper foil.