Quasi‐TEM Rectangular Waveguides with Frequency Selective Surface Walls: Part I–Electrical Properties and Geometrical Characteristics

Abstract

Electrical properties and geometrical characteristics of frequency‐selective‐surface‐loaded quasi‐transverse electromagnetic (TEM) rectangular waveguides are investigated in detail. The properties of electrical field distributions over the cross section of waveguides at various periodical phase shift points are studied. The phenomena, in connection with artificial magnetic conductor (AMC), cavity resonance, and surface resonance, are discussed. A definition of bandwidth for AMC is proposed on the basis of the variation of average z‐polarized electric fields along z‐axis between two side dielectric surfaces. Standard deviation technique is used to describe the uniformity of electrical fields and cavity efficiency is defined to represent the percentage of useful cavity with uniform electrical fields. The dispersion relationship, bandwidths of AMC and single mode, and cavity efficiency for various types of AMC surfaces are examined and compared. The geometrical characteristics of quasi‐TEM waveguides are studied in both theory and experiment. Design rules for high‐quality quasi‐TEM waveguides are proposed. Copyright © 2013 John Wiley & Sons, Ltd.