Optimization of a Printed UWB Antenna: Application of the invasive weed optimization algorithm in antenna design

This article presents a general approach to design and optimize printed ultrawideband (UWB) antennas by using invasive weed optimization (IWO), a well-known global optimization algorithm. To achieve the required radiation parameters over a wide bandwidth, a frequencyrelated cost function with optimal weighting coefficients is suggested. Two prototypes of the optimized antenna have been manufactured and examined. The experimental outcomes show good agreement with the simulated ones that validate the proposed optimization approach. The optimized antenna has a compact size of 50 mm × 50 mm. The operational bandwidth of the antenna for S₁₁ < -10 dB, from both measurement and simulation, is 150%, based on the center frequency of 6.4 GHz (1.6-11.2 GHz), which also covers the UWB (3.1-10.6 GHz) applications. The time-domain response of the antenna was also investigated by measurement of the group delay. Finally, the efficiency of the optimized antenna in terms of bandwidth, size, and gain are compared with a number of previously proposed designs. Comparison results show that the optimized antenna outperforms other designs cited. The experimental outcomes in frequency as well as the time domain show that the antenna is suitable for use in UWB or other communication systems.