Wiring like mother nature [antenna design]

Today, most antenna designs are simulated numerically rather than analyzed theoretically. A computer program approximates the structure and calculates its properties. Even though very complex designs can be simulated, structures are usually kept simple to allow for easy understanding and analysis. Symmetry is often present. Nearly all the designs "make sense" when one looks at them or their circuit schematics. This is not necessarily the case for antennas designed using a genetic algorithm (GA). We illustrate this automated design technique on two types of wire antennas. The first is a Yagi-type antenna that is optimized to have different electromagnetic characteristics from a conventional Yagi. The second is radically different from a typical antenna: a seemingly arbitrary structure of seven wires connected in a series and confined to a specified volume; the actual shape is completely determined by the GA.