The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.
This award will support a twenty-four-month research fellowship by Dr. Shikik T. Johnson to work with Dr. Antonio Scaglione at the University of Salerno in Italy.
The task of the present research project is to analyze the interaction between electromagnetic (EM) guided waves and layered dielectric structures characterized by fractal geometry. Fractals are self-similar structures characterized by invariance property with respect to an iterative change of scale [1]. They can be obtained by performing a basic operation (generator) on a dimension to smaller and smaller scale. The triadic Cantor fractal, which is quite possibly one of the simplest fractal geometries, is obtained starting from a line segment of length L, and removing its middle portion of length L/R (R>1) in successive steps. As this procedure is repeated on each segment in a set, or layer of, e.g., dielectric material, the shape of the overall structure takes form. This repeated iterative process is known as a growth stage. Halting the growth process after a finite number of steps gives what is known as a triadic Cantor prefractal. These structures exhibit forbidden frequency bands in their electromagnetic response (Electromagnetic Band Gap, EBG) and are intensively studied for their potential applications as filters, reflectors, and sensors in both optical and microwave frequency range.
