Phase noise resonator measurement bench using DDS as excitation source

Accuracy of resonator phase noise measurement systems in a passive method depends on the stability of the excitation source. Good accuracy over a quite large frequency range is needed because of the various resonant frequencies of the resonators studied. In this paper, Direct Digital Synthesis solution is investigated as excitation source of measurement bench. Various stability measurements on this source are presented. Phase noise floor of the passive measurement system is given as well as results of pairs of quartz crystal resonators. Finally, limitations presented by this synthesizer applied to phase noise measurement systems, are discussed.