Signal generators are used in test and measurement in the study, production and maintenance of analogue and digital electronic equipment. Almost all of the products are now based on the principle of frequency synthesis, ie the generated signal is locked in phase on a reference frequency produced by a quartz oscillator or an external frequency standard. The RF generators are in principle equipped with a modulation generator to simulate the various types of analog and digital modulations. To test radars, the generators must include a modulator / pulse generator. The possibility of IQ signal modulation has become widespread (vector modulation), even for entry-level devices, in order to test the behavior of 3G and WLAN radiocommunications equipment. The arbitrary wafeforms generators (AWG) stores in memory the samples corresponding to a particular waveform defined by the user. These samples are converted by a digital / analog conversion system to generate the corresponding signal.