Abstract
In this article, the effect of an irregular-fractal slot added to a radiating square patch of an ultrawideband (UWB) printed antenna is studied. The fractal complex-shaped slot was generated randomly by applying the Cellular-Automata technique. Analysis of both simulated and measured results dealing with the impedance matching, surface currents, gain, and radiation patterns shows three different behaviors: improvement, mismatching, or rejection of one or two bands, depending on the shape and position of the slot. It is found also that the gain of the UWB-antenna can be enhanced for some particular shaped slots. (c) 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2506-2514, 2015