An ultra-low-power atomic clock push toward intelligent IoT

Scientists at Tokyo Tech, Ricoh co. and The National Institute of Advanced Industrial Science and Technology have developed an ultra-low-power atomic clock (ULPAC) for small satellites to enable future communication systems beyond 5G.

Prototype of the atomic clock (33 mm x 38 mm x 9 mm) A newly developed compact ULPACs, mounted on small satellites, automobiles, and smartphones, accelerate the realization of seamless and on-demand mobile communication networks.
Prototype of the atomic clock (33 mm x 38 mm x 9 mm) A newly developed compact ULPACs, mounted on small satellites, automobiles, and smartphones, accelerate the realization of seamless and on-demand mobile communication networks.

As present telecommunication innovations keep on developing, the speed and sheer amount of data required by users also increases. One way to satisfy this need is by using a constellation of nano- or micro-scale satellites that circle the planet in low earth orbit.

Such swarm of satellites requires extremely precise synchronization to a global time standard, for which a very precise atomic clock on board each unit is necessary.

Due to the large size of the conventional clock that consumes too much power, they can’t be installed on small satellites. Considering this issue, scientists at the Tokyo Tech, Ricoh co. and The National Institute of Advanced Industrial Science and Technology have developed an ultra-low-power atomic clock (ULPAC) for small satellites to enable future communication systems beyond 5G.

Scientists develop these quantum atomic clocks using a method called coherent population trapping. Based on this method, scientists have recently designed a fully functional atomic clock that surpasses the current industry benchmarks. The phase-locked loop in this clock consumes an order of magnitude less power than that of previously reported devices.

Moreover, the proposed atomic clock surpasses at presently detailed gadgets in two other basic viewpoints: volume occupied and Allan deviation. Since powerful utilization of the accessible space on board nano/smaller scale satellites is of the substance, so is ensuring that the last plan can be made to fit an extremely little volume.

With respect to Allan deviation, it is a proportion of the steadiness of the frequency of a clock; a low Allan deviation suggests a truly steady and reliable clock. The atomic clock created by the group is likewise looking great in these two fronts too.

The integrated quantum package The quantum package of the proposed low-power atomic clock fits in a volume even smaller than the smallest atomic clocks currently available.
The integrated quantum package
The quantum package of the proposed low-power atomic clock fits in a volume even smaller than the smallest atomic clocks currently available.

Associate Professor Kenichi Okada from Tokyo Tech said, “The prototype of our atomic clock achieves a long-term Allan deviation of 2.2×10−12 at τ=105 s (the industry standard is 3.0×10−10 at τ=1 s) while occupying a volume of only 15.4 cm3 (slightly smaller than the smallest currently available atomic clock).”

“According to the research team, there is room for improvement. The total power consumption is 59.9 mW, which is mainly because of the microcontroller unit in this prototype and can be further reduced by using custom logic circuitry.”

The final result of this collaboration is a prototype of a very promising atomic clock that pushes current benchmarks further so that future telecommunications systems, such as those beyond 5G, can become a reality.