In this study, in order to amplify the radiation at Terahertz (THz) photoconductive antennas, metal nanoparticles are used in semiconductor layers based on plasmonic principles. The use of nanoparticles between antenna electrodes and semiconductor layers not only enhances the THz radiation intensity but also changes the radiation frequency peak. The changes of electric charge carriers versus the strike of laser pulses and the production of an electric current on the antenna surface are simulated with the COMSOL Multiphysics software through the FEM method. The changes of the electric current at the semiconductive surface generate electric field radiation. This has been simulated using the CST STUDIO software through the FDTD method.