Modeling of transmission lines with multiple coated conductors

The Gradient Model primary developed to describe skin effect in rough surfaces also allows to model stacks of thin layers with different conductivity. Due to its modeling approach, utilizing a location dependent conductivity, penetration of the magnetic field through layers of different conductivity can be precisely predicted. From that, impact on damping and propagation delay is calculated. In this paper, the skin effect in rough, layered conductors is calculated and the simulation results are compared to measurement data from a commercially available PC1.85mm precision air-line. The indicated method is not limited to coaxial transmission lines. It is applicable in field solvers as well as it is for analytical two-wire transmission line models, using the proposed concept of an equivalent circumference.