Editor's comments

摘要

The cover figure for this issue shows the near-zone electromagnetic field power density in the vicinity of a two-layer frequency-selective surface made from unit cells that have U-shaped elements. Frequency-selective surfaces are interesting both because of their physical (electromagnetic scattering) properties and because of their computational modeling properties. They depend on resonant structures to operate, and those very resonances produce fascinating electromagnetic and computational properties. These are explored in Özgür Ergül's Solution Box contribution by Özgür Eriş, Hande İbili, and Özgür Ergül. They considered three such structures, having three different arrangements of U-shaped unit cells. As an example of their results from an electromagnetic scattering standpoint, they showed that two different structures made from layers with identical unit cells but arranged in different orientations had significantly different scattering properties. In particular, one version of the structure had very similar responses to both left-hand and right-hand circularly polarized waves, whereas the other did not. From a computational standpoint, the most challenging frequencies for analysis in terms of number of iterations required for convergence of the solution were not the same as the frequencies at which element resonances occurred. All of this makes for quite interesting reading.