Fractal antenna engineering: The theory and design of fractal antenna arrays

A fractal is a recursively generated object having a fractional dimension. Many objects, including antennas, can be designed using the recursive natur e of a fractal. In this article, we provide a comprehensive overview of rec ent developments in the field of fractal antenna engineering, with particul ar emphasis placed on the theory and design of fractal arrays. We introduce some important properties of fractal arrays, including the frequency-indep endent multi-band characteristics, schemes for realizing low-sidelobe desig ns, systematic approaches to thinning, and the ability to develop rapid bea m-forming algorithms by exploiting the recursive nature of fractals. These arrays have fractional dimensions that are found from the generating subarr ay used to recursively create the fractal array. Our research is in its inf ancy, but the results so far are intriguing, and may have future practical applications.