Violetti, MaddalenaPellaton, MatthieuAffolderbach, ChristophMerli, FrancescoZuercher, Jean-FrancoisMileti, GaetanoSkrivervik, Anja K.2015-02-202015-02-202015-02-20201410.1109/Jsen.2014.2326337https://infoscience.epfl.ch/handle/20.500.14299/111565WOS:000346791700035Nowadays mobile and battery-powered applications push the need for radically miniaturized and low-power frequency standards that surpass the stability achievable with quartz oscillators. For the miniaturization of double-resonance rubidium (Rb-87) atomic clocks, the size reduction of the microwave cavity or resonator (MWR) to well below the wavelength of the atomic transition (6.835 GHz for Rb-87) is of high interest. Here, we present a novel miniaturized MWR, the mu-LGR, for use in a miniature DR atomic clock and designed to apply a well-defined microwave field to a microfabricated Rb cell that provides the reference signal for the clock. This mu-LGR consists of a loop-gap resonator-based cavity with very compact dimensions (<0.9 cm(3)). The beta-LGR meets the requirements of the application and its fabrication and assembly can be performed using repeatable and low-cost techniques. The concept of the proposed device was proven through simulations, and prototypes were successfully tested. Experimental spectroscopic evaluation shows that the beta-LGR is well-suited for use in an atomic clock. In particular, a clock short-term stability of 7 x 10(-12) tau(-1/2) was measured, which is better than for other clocks using microfabricated cells and competitive with stabilities of compact Rb clocks using conventional glass-blown cells.Microwave devicesmicrowave measurementsatomic measurementsspectroscopyfrequency controlmetrologytext::journal::journal article::research article