|Fractal antenna designs
(see Hohlfeld and Cohen)
can overcome some of these problems. Experiments have shown that
antennas built with only a small number of iterations of a fractal process can exhibit
sensitivity at several frequencies. As the number of iterations increases, the
lowest frequency of the antenna gets lower, and additional higher frequencies are
added. Also, fractal antennas can operate efficiently at one-quarter the size
of more traditional designs. Properly harnessed, these features represent
real advantages. Several companies already are using fractals for compact,
multifrequency antennas in cellular phones and military communications hardware.
Fractal Antenna Systems,
a company founded by Nathan Cohen,
has built a Sierpinski carpet cellular phone antenna fitting inside the
body of the phone, and the multifrequency aspect of the antenna will allow GPS to be incorporated in
the phone. Other applications include compact, multifrequency wireless LAN and maritime antennas.
Several Fractal Antenna System designs are shown below.|