Propagation Along a Thin Insulated Conductor Parallel to Interfacing Homogeneous Half-Spaces

This article extends the solution to an electromagnetic wave propagating along a thin wire parallel to the interface between two homogeneous half-spaces to wires coated with insulation. The solution presented in this article includes half-spaces with different magnetic permeability and wires with finite conductance. The solution agrees with earlier works after appropriate restrictions are applied. The effects of varying the parameters representing the half-spaces and conductor insulation on the system attenuation constant are investigated. Equivalent line parameters for the propagation are extracted from the full wave modal equation and analytical approximations of these parameters are provided for conductors located above or below the interface assuming the half-spaces are formed by the earth and air. The limitations of the approximations are investigated and compared with previous approximations that have been identified as used outside the range of their applicability. As well as reviewing some of the more fundamental works on the subject, this article contributes to understanding the limitations of existing theory and establishes an alternate process for further extensions in the field.