Fractal structures and their application in antenna design

Document Type : Original Article

Author

Faculty of Engineering, University of Garmsar

Abstract
Fractal geometry was first introduced in 1975 by Mr. Mandelbrot. Fractal shapes are used to model natural phenomena that cannot be expressed by Euclidean geometry, such as clouds, tree leaves, sea shores, etc. The characteristic of fractal shapes is that these shapes are self-similar, so that each part of these shapes is actually a small scale of the whole shape. Trees are a clear example of this feature, the stems and branches of trees and even leaves are actually a smaller scale than the tree itself. Today, the use of fractals in physics, chemistry, biology, economics, geology, image processing, computer graphics, antenna design, etc. is widespread. The use of fractal geometry in electromagnetic problems has become a new and interesting topic. The research and study for the use of these mathematical functions in scattering problems, array techniques, improvement of input impedance matching, size reduction and multiband antennas. Recently, it has been tried to use fractal geometry in the design of antennas. The use of fractals in the design of antennas has advantages that encourage designers to use them. In this article, some examples of fractal structure have been introduced and their application in antenna design has been reviewed.