title: A low phase noise microwave frequency synthesis for a high-performance cesium vapor cell atomic clock.
abstract: We report the development, absolute phase noise, and residual phase noise characterization of a 9.192 GHz microwave frequency synthesis chain devoted to be used as a local oscillator in a high-performance cesium vapor cell atomic clock based on coherent population trapping (CPT). It is based on frequency multiplication of an ultra-low phase noise 100 MHz oven-controlled quartz crystal oscillator using a nonlinear transmission line-based chain. Absolute phase noise performances of the 9.192 GHz output signal are measured to be -42, -100, -117 dB rad(2)/Hz and -129 dB rad(2)/Hz at 1 Hz, 100 Hz, 1 kHz, and 10 kHz offset frequencies, respectively. Compared to current results obtained in a state-of-the-art CPT-based frequency standard developed at LNE-SYRTE, this represents an improvement of 8 dB and 10 dB at f = 166 Hz and f = 10 kHz, respectively. With such performances, the expected Dick effect contribution to the atomic clock short term frequency stability is reported at a level of 6.2 × 10(-14) at 1 s integration time, that is a factor 3 higher than the atomic clock shot noise limit. Main limitations are pointed out.
authors.affiliation: FEMTO-ST, CNRS, Université de Franche-Comté, 26 chemin de l'Epitaphe, 25030 Besançon, France.
authors.forename: B
authors.initials: B
authors.lastname: François
authors.affiliation: INRIM, Strada delle Cacce 91, 10135 Torino, Italy.
authors.forename: C E
authors.initials: CE
authors.lastname: Calosso
authors.affiliation: LNE-SYRTE, Observatoire de Paris, CNRS-UPMC, 61 avenue de l'Observatoire, 75014 Paris, France.
authors.forename: J M
authors.initials: JM
authors.lastname: Danet
authors.affiliation: FEMTO-ST, CNRS, Université de Franche-Comté, 26 chemin de l'Epitaphe, 25030 Besançon, France.
authors.forename: R
authors.initials: R
authors.lastname: Boudot