Calculations on surface-wave transmission lines with unrestricted radial dimensions

Accurate expressions for power flow, power loss per unit length and attenuation coefficient are derived by the perturbation method. It is shown that the approximations used by Goubau, and hitherto generally applied, result in errors which increase rapidly for large values of phase-velocity reduction. Computations based on the accurate expressions for the TM01 mode are presented in the form of a design chart.