The principal goal of the thesis is to analyze the radiation and scattering of Wi-Fi antennas and optimization of the design of Wi-Fi antennas. Investigation of the optimum design parameters for improved effective efficiency of the antennas. Designing the antennas with desired efficiency at different frequency ranges and implementing the same optimization for the antenna array designs and investigate the improvement in the output transmission of the antennas. The particular antennas under study for the scope of this thesis has been applied in Wi-Fi applications.