[IMSAI Guy] tore apart a device with a wireless network card and decided to investigate what was under the metal can. You can see the video of his examination below. Overall, it was fairly unremarkable, but one thing that was interesting was its use of an antenna on the PCB that uses a fractal design.
You probably know fractals are “self-similar” in that they are patterns made of smaller identical patterns. The old joke is that the B. in Benoit B. Mandelbrot (the guy who coined the term fractal) stands for Benoit B. Mandelbrot. You can think of it as akin to recursion in software. Antennas made with fractal patterns have some unusual and useful properties.
These antennas were developed in 1988 by [Nathan Cohen] and published in 1995, even though log periodic antennas were already in use that used unrecognized fractal properties. Like log periodics, but unlike most other antennas, fractal antennas can be very broadband. The reason is that the fractal structure creates virtual combinations of capacitors and inductors that provide many different resonances.
Of course, the design of these can be challenging and is often done via simulation. There are also detractors that say fractal antennas don’t really work better. If you want to see something practical check out this thesis from several students at Nirma University which uses simulation to design such an antenna and look at its performance.