A Transmission Line Approach for Rough Conductor Surface Impedance Analysis

This work proposes a transmission line approach to determine the surface impedance of conductors with rough surfaces. Based on the gradient model, the roughness is represented by a gradual transition of the intrinsic impedance. Discretization and successive impedance transformations then directly yield the surface impedance. Evaluating the fields is not necessary to this end, but still feasible if required. Investigations of the proposed model confirm the field diffusion to be fully characterized by a single dimensionless ratio, which enables a comprehensive analysis of the surface impedance regarding its dependency on frequency, conductivity, and roughness.