Transformation Method for PTD Symmetric Edge Waveguide

摘要

This paper investigates the properties of a particular kind of edge waveguide consisting of a combination of perfect electric and perfect magnetic walls. It is shown that this waveguide supports the propagation of a mode protected against backscattering from local perturbations. The exact expression of this mode is derived through a conformal transformation approach. The protection against backscattering is a consequence of Parity-Time reversal - Duality (PTD) symmetry, which enables unidirectional propagation in reciprocal media. An example of practical implementation of this waveguide structure is also presented and numerically analyzed.