The Microloop-Gap Resonator: A Novel Miniaturized Microwave Cavity for Double-Resonance Rubidium Atomic Clocks

Nowadays 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 (