Expressions for the conductor loss of strip-line and coplanar-strip (CPS) structures

In this paper, we present closed-form expressions for the attenuation constant due to conductor loss for strip-line and coplanar-strip (CPS) structures. These expressions are functions of a universal parameter referred to as the stopping distance, where it is shown that this stopping distance is a function only of the local edge geometry, i.e., the strip thickness, the shape of the edge, and the material of the strip conductor. We also present an expression for the current distribution of the ground planes of a strip-line structure, which is used to derive an expression for the conductor loss of the ground planes. Results obtained with these loss expressions are compared to, and closely agree with, both experimental results and full-numerical results found in the literature for these two structures.