In order to perform photonic mixing and Radio Frequency (RF) generation by frequency up-conversion, the authors analyze the use of a single Semiconductor Optical Amplifier (SOA) and a Semiconductor Optical Amplifier-Mach-Zehnder Interferometer (SOA-MZI) structure by computer simulation using Advanced Design System (ADS) software. It assesses and compare both devices in terms of RF conversion gain and Cross Gain Modulation/Cross Phase Modulation (XGM/XPM) bandwidth. The simulations were carried out as function of several bias currents by mixing one and two optical input signals. Results have shown that SOA-MZI presents an average RF conversion gain 1 dB higher than single SOA.