Quasi-TEM modes in rectangular waveguides: a study based on the properties of PMC and hard surfaces

TL;DR

This paper investigates the propagation mechanisms of quasi-TEM modes in rectangular waveguides using PMC and hard surfaces, providing basic rules and analyzing their reflection properties to understand mode behavior.

Contribution

It introduces a simplified analysis approach for quasi-TEM modes based on surface reflection properties, filling gaps in the understanding of their propagation mechanisms.

Findings

Quasi-TEM modes exhibit nearly uniform field distribution.

Dispersion curves can be derived from surface reflection analysis.

Reflection properties determine mode characteristics.

Abstract

Hard surfaces or magnetic surfaces can be used to propagate quasi-TEM modes inside closed waveguides. The interesting feature of these modes is an almost uniform field distribution inside the waveguide. But the mechanisms governing how these surfaces act, how they can be characterized, and further how the modes propagate are not detailed in the literature. In this paper, we try to answer these questions. We give some basic rules that govern the propagation of the quasi-TEM modes, and show that many of their characteristics (i.e. their dispersion curves) can be deduced from the simple analysis of the reflection properties of the involved surfaces.