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.