Scattering and radiation characteristics of step discontinuity in double-negative slab waveguide operating in evanescent surface mode

The scattering and radiation characteristics of a step discontinuity in double-negative (DNG) slab waveguide operating in evanescent surface mode are analyzed. The dispersion properties of the grounded planar DNG slab waveguide for ordinary and evanescent surface modes are examined, from which the left-hand property of the operating mode is testified. The relative scattered power and radiation pattern of the step are given for the first time, from which the backward radiation of the stepped DNG guide is clearly demonstrated. In the analysis the radiation problem is ended a propagation problem of all the space eigenmodes, which tremendously simplifies the calculation procedure