An Ultra-Miniature Cell-Type Rb Atomic Clock Based on a Novel Waveguide Cavity

Abstract

We introduce a novel waveguide cavity for ultra-miniature cell-type Rb atomic clock. In the cavity, a coupling ring shaped to be a semi-circle imports an rf signal from electronics, a screw regulator acts as a medium coupler to transmit the microwave signal into the absorption cell, and both the parts serve as a filter to suppress useless components except 6.8 GHz. Furthermore, the waveguide cavity can be used to design a miniature Rb atomic clock, and spread it to a chip-scale atomic clock. We have completed the design of the smallest cell-type Rb atomic clock in the world based on this waveguide cavity. It has not only a small size but also obviously better key performances than those of other miniature Rb atomic clocks. This ultra-miniature cell-type Rb atomic clock aging is 4 × 10 −13 /d, which is obviously slower than that of other miniature Rb atomic clocks.

Direct Digital Frequency Control Based on the Phase Step Change Characteristic between Signals

“…There is a greatest common factor frequency 𝑓 maxc between the two signals, 𝑓 1 = 𝐴𝑓 maxc , 𝑓 2 = 𝐵𝑓 maxc , and the least common multiple period 𝑇 minc is equal to 1/𝑓 maxc . [9] f2 f1 Tminc Tminc Fig. 1.…”