A brief discussion on the different formulations of the coupled mode method in chiral media: Application to the parallel‐plate chirowaveguide

Abstract

ABSTRACT:The application of the coupled-mode method (CMM) for calculating the propagation constants and the electromagnetic-field distribution in chirowaveguides is well known. In this paper, two different formulations of the method are revised and compared, and are then extended to partially filled parallel-plate waveguides.

Electromagnetic propagation in unbounded inhomogeneous chiral media using the coupled mode method

“…On the one hand, we have shown that for isotropic or anisotropic (ferrite) materials [5,6] and for ICM [11] our EHI-formulation gives more accurate results than an EHD-type formulation, especially for high values of the constitutive parameters. On the other hand, the most appreciable differences in the results of the electromagnetic field provided by the EB-and the EH-formulations [10,14] are observed in the proximity of the PEC's bounding the ICM, with these differences decreasing near the center of the waveguide. In this article, we are going to simulate an unbounded ICM, with the PEC's (see Fig.…”

Numerical Modeling of Electromagnetic Wave Propagation Through Bi-Isotropic Materials

“…The Coupled Mode Method is one of the available numerical methods in the frequency domain used for analyzing the electromagnetic wave propagation inside waveguides that contain any isotropic, anisotropic or complex medium [63][64][65][66][67][68][69]. Originally, this method was formulated by Schelkunoff [63] for uniform closed structures involving heterogeneous and non-isotropic media.…”

Numerical study of electromagnetic wave propagation through layered structures with chiral media

“…It is worth to mention that there are two different formulations of the CMM for the analysis of electromagnetic wave propagation in a waveguide. These are the EH and EB formulations 10, 11 and their main difference reside in the primary expanded fields of each formulation. When a waveguide is filled by a chiral medium, the EB formulation obtains better results than the EH one, as the electromagnetic field verifies all boundary conditions in the metallic walls of the waveguide 10.…”

“…These are the EH and EB formulations 10, 11 and their main difference reside in the primary expanded fields of each formulation. When a waveguide is filled by a chiral medium, the EB formulation obtains better results than the EH one, as the electromagnetic field verifies all boundary conditions in the metallic walls of the waveguide 10. The most appreciable differences in the results of the electromagnetic field of the two formulations are in the proximity of the PEC, decreasing as we are approaching the center of the waveguide 10.…”

“…In the first case, we have developed a finite‐differences in the time domain (FDTD 4) technique, modified to model bi‐isotropic media 5, 6, and adapted it to the case under study. In the frequency domain, we have extended a hybrid technique, based on the coupled‐mode method (CMM, which is originally formulated for closed structures) and the mode‐matching method (MMM) 7–11, to open structures 12 composed of an arrangement of an unlimited number of bi‐isotropic slabs placed along the propagation direction. The MMM is included to characterize discontinuities in the power propagation direction of a structure composed of a number of chiral slabs 7, 13.…”