An internal Ultra-Wideband (UWB) monopole antenna for use in portable wireless communication
applications is presented with a compact dimensions. It consists of a radiating patch, a matching stub, and a
ground plane. The effect of defected ground plane structure (DGS) is studied in addition to the effect of defected
slots in the radiating patch and matching stub on the return loss (Sll)' The Differential Evolution (DE) algorithm is
considered to minimize S II in the UWB frequency range by determining the appropriate antenna dimensions, the
results are compared with other optimization techniques such as Genetic Algorithm (GA) and Particle Swarm
Optimization (PSO). Also, the proposed antenna is built into a plastic case (C:r = 3), having external dimensions
43.4 x 21.4 x 8.3 mm to study its effect on the radiation parameters