Analytic Modelling of a Planar Goubau Line with Circular Conductor

TL;DR

This paper develops an approximate analytical model for the surface wave propagation along a planar Goubau line with a circular conductor, validated by numerical simulations and experimental data, advancing understanding of its behavior.

Contribution

It introduces the first approximate analytical equation for the propagation constant of a planar Goubau line with a circular conductor, validated by simulations and experiments.

Findings

Propagation constant depends on system parameters.

Excellent agreement with numerical simulations.

Validation against experimental phase velocity measurements.

Abstract

This paper analyses the surface wave mode propagating along a simplified planar Goubau line consisting of a perfectly conducting circular wire on top of a dielectric substrate of finite thickness but infinite width. An approximate equation for the propagation constant is derived and solved through numerical integration. The dependence of the propagation constant on various system parameters is calculated and the results agree well with full numerical simulations. In addition, the spatial distribution of the longitudinal electric field is reported and excellent agreement with the numerical simulation and previous studies is found. Moreover, validation against experimental phase velocity measurements is also reported. Finally, insights gained from the model are considered for a Goubau line with a rectangular conductor. These results present the first step towards an analytic model of the planar Goubau line.