Microwave atomic clocks are timing devices in which the microwave oscillator is stabilized to
the hyperfine transition of alkali atoms. Owing to their excellent precision and stability, the
atomic clocks are deployed on space satellites or base stations and commonly used as a
time and frequency standard for the localization and synchronization of communication
devices including untethered sensor networks. Commercial atomic clocks are currently of
rack-mount size and sufficiently small. However, if the size of such atomic clocks is further …