A Robust Method for Solving the Modal Fields in Radially Unbounded Cylindrical Waveguides With Two Layers Under Extreme Conductive Conditions

In this article, we present a numerically stable formulation for the electromagnetic analysis of lossy circular waveguides. The associated boundary value problem is solved analytically via an appropriate set of scaled cylindrical functions. A new numerically stable characteristic equation that simplifies the application of Cauchy’s argument principle is introduced. Numerical results are presented and show that the proposed approach can solve modal fields even in extreme lossy scenarios.