The synthesis of wideband arrays using nature-based design concepts

In order to meet the growing demands of modern radar and communication systems, engineers often turn to nature for their inspiration. Genetic algorithms (GA), optimization techniques based on the Darwinian notion of survival of the fittest, have recently been applied to find solutions to these complex design problems. In addition, complicated geometries of many natural objects such as trees, ferns, coastlines, and vascular systems could be described simply with the advent of fractal geometry. Fractal geometry has also been applied to create a class of antenna arrays, called fractal-random arrays, which combine the physical and electrical properties of periodic and random arrays into one design. In previous research, The authors introduced a specialized subset of fractal-random arrays, that is now called polyfractal arrays, which are particularly adept in genetic algorithm optimization. In addition, the authors introduced a new type of nature-based design process which applies a robust genetic algorithm technique to evolve optimal polyfractal array layouts. In this paper, the authors consider several nature-based design examples, which illustrate that optimized fractal-random arrays can possess extremely large bandwidths.