For an important research institute, Florence Engineering developed a Ku-band CW synthesizer with high frequency stability for atmospheric vapor monitoring applications. The system was in fact employed by the end user within his own system which involves the installation of a double frequency radio link extending a few tens of kilometers which, crossing the atmosphere horizontally, is subject to attenuation resulting from the content of water vapor. Through the information derived from the differential attenuation between the two used frequencies (NDSA – Normalized Differential Spectral Attenuation), the end user validated their atmospheric vapor profiling algorithms. The effectiveness of the developed hardware platform was demonstrated by the extensive scientific literature produced by the customer.