Mode Bifurcation and Fold Points of Complex Dispersion Curves for the Metamaterial Goubau Line

TL;DR

This paper compares the complex dispersion curves of dielectric and metamaterial Goubau lines, revealing unique features like mode bifurcation, fold points, and mode merging in the metamaterial case.

Contribution

It introduces the analysis of complex dispersion curves for metamaterial Goubau lines, highlighting their distinct bifurcation and fold point phenomena not seen in dielectric lines.

Findings

Metamaterial Goubau lines exhibit mode bifurcation and complex fold points.

Distinct merging of complex and real modes occurs in metamaterial lines.

The dispersion curve structure is significantly different for metamaterials.

Abstract

In this paper the complex dispersion curves of the four lowest-order transverse magnetic modes of a dielectric Goubau line ($\epsilon>0, \mu>0$) are compared with those of a dispersive metamaterial Goubau line. The vastly different dispersion curve structure for the metamaterial Goubau line is characterized by unusual features such as mode bifurcation, complex fold points, both proper and improper complex modes, and merging of complex and real modes.