Wave propagation inside a two-dimensional perfectly conducting parailel-plate waveguide: hybrid ray-mode technioues and their visualizations

Abstract

This article is intended as an educational aid, dealing with high-frequency (HF) electromagnetic wave propagation in guiding environments. It is aimed at advanced senior and first-year graduate students who are familiar with the usual engineering mathematics for wave equations, especially analytic functions, contour integrations in the complex plane, etc., and also with rudimentary saddle-point (HF) asymptotics. Afler an introductory overview of issues and physical interpretations pertaining to this broad subject area, detailed attention is given to the simplest canonical, thoroughly familiar, test environment: a (timeharmonic) line-source-excited two-dimensional infinite waveguide with perfectly conducting (PEC) plane-parallel boundaries. After formulating the Green's function problem within the framework of Maxwell's equations, alternative field representations are presented and interpreted in physical terms, highlighting two complementary phenomenologies: progressing (ray-type) and oscillatory (mode-type) phenomena, culminating in the self-consistent hybrid ray-mode scheme, which usually is not included in conventional treatments at this level. This provides the analytical background for two educational MATLAB packages, which explore the dynamics of ray fields, mode fields, and the ray-mode interplay. The first package, RAY-GUI, serves as a tool to compute and display eigenray trajectories between specified sourcelobserver locations, and to analyze their individual contributions to wave fields. The second package, HYBRID-GUI, may be used to comparatively display range andlor height variations of the wave fields, calculated via ray summation, mode-field summation, and hybrid ray-mode synthesis.

A New Electromagnetic Engineering Program and Teaching via Virtual Tools

“…The packages RAY/HYBRID [15], WEDGE [16] and DiSLAB are designed in Matlab using mathematical solutions, therefore are very important to teach ray-mode representations in 2D parallel plate, wedge-type and slab waveguides, respectively. TM characteristics of these three structures are almost canonical and covered in most of the classical EM lectures.…”

“…The same is true for the WEDGE and DiSLAB virtual tools. The 2D parallel plate waveguide with penetrable and non-penetrable boundaries are canonical structures in teaching rays representation, eigenvalue (source-free) and Green's function (source-driven) problems [15,16]. SNELL [17], MGL-2D [11], GrSSPE [13], GrMoMPE [5] and DrMIX [6] are 2D propagators based on different frequency or time domain methods.…”

“…Classical 2D parallel plate waveguide with penetrable as well as non-penetrable boundaries are discussed in this course. Ray, mode and hybrid solutions are presented together with the visual capabilities of the RAY, HYBRID [15] and DiSLAB virtual tools. Ray-mode representations and ray shooting methods are covered in this lecture.…”

“…Triggered by these facts, discussions and thoughts we have developed and introduced multipurpose EM virtual tools [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] that can be used in most of the classical EM lectures as well as in novel EM Engineering Programs (EMEP), and have been discussing them internationally [19][20][21][22][23][24]. We have always looked for something which would be useful, give physical insight, and effective so that the young EM researchers and students can use intelligently.…”

Digicomm: A MATLAB-Based Digital Communication System Simulator

“…These necessitate the establishment of an intelligent balance between real and virtual experimentation [1,2]. Triggered by these thoughts, we have developed and hosted several virtual tools (simulation packages) to the use of readers in the Magazine for the last decade or so [3][4][5][6][7][8][9][10][11][12][13]. These packages can be used as effective engineering tools, as well as virtual lab environments in Under graduate-and graduate-level electromagnetics lectures.…”