The Chip-Scale Atomic Clock

Our armed forces depend on precise time for reliable and secure communications, positioning, and navigation. For over 30 years, Symmetricom has been supplying modular and ruggedized atomic clock solutions that have met our military’s mobile needs. However, with the increased power of information and communication, there is an emerging need for more portable, battery-powered instruments. Since 2002, in collaboration with the Defense Advanced Research Projects Agency (DARPA), Symmetricom has been developing a Chip-Scale Atomic Clock (CSAC) one-hundred times smaller and lower power than any existing atomic clock technology. Symmetricom is proud to support the extension of precise timing through what is regarded as the “last mile” of the military communications network. These advances in atomic clock technology will increase the safety, security, and capability of each and every foot soldier.

In the commercial marketplace, the low cost and high performance timing signals provided by CSAC will enable a new generation of high-bandwidth devices for accurate and secure communications, positioning, and timing. Applications include secure portable communications, personal navigation, robotics, online gaming, and more.

For further technical information about Symmetricom CSAC technology, please click here.

For information regarding the pricing and availability of Symmetricom CSAC technology, prototype evaluation, or to join our mailing list, please contact: info@symmttm.com

The DARPA CSAC Program

The DARPA Chip-Scale Atomic Clock (CSAC) program began with a workshop at the National Institute of Standards and Technology (NIST) in March 2001. Following the workshop, DARPA initiated a competitive call for proposals to demonstrate the feasibility of a CSAC. Symmetricom, leading a development team which includes The Charles Stark Draper Laboratory and Sandia National Laboratories, was awarded a Phase I contract, in May 2002, to investigate, theoretically and experimentally, the feasibility of very small ("chip scale") atomic clocks. In 2002 and 2003, the Symmetricom-led team published a series of papers and filed several patent applications on the fundamental physics and technology of chip-scale atomic clocks. In late 2003, the team completed the Phase-I DARPA milestones and demonstrated a laboratory-scale atomic clock, based on CSAC components, which exceeded DARPA’s ultimate performance objectives by nearly an order of magnitude. In January 2004, Symmetricom advanced to Phase-II of the DARPA contract, to develop prototype chip-scale physics packages and low-power clock electronics. The principal goal of the Phase II program was to develop an operational laboratory prototype with compliant short-term frequency stability. In April 2005, Symmetricom demonstrated a 10 cc, 200 mW Miniature Atomic Clock (MAC) which surpassed DARPA's stability objectives (see, The World’s Smallest Atomic Clock, below). In August, 2005, Symmetricom advanced to Phase-III of the DARPA CSAC program with two main objectives. In Phase-III, the Symmetricom-led team will continue to evolve the CSAC technology to a smaller size and lower power, and to demonstrate a laboratory prototype of a 1 cc, 30 mW atomic clock. At the same time Symmetricom will continue to refine the Miniature Atomic Clock (MAC), developed in Phase-II and to make a number of prototype MACs available to systems integrators for proof-of-concept insertion demonstrations.

The World’s Smallest Atomic Clock

In Phase-II of the DARPA program, the Symmetricom-led CSAC team demonstrated a prototype Miniature Atomic Clock (MAC) as an intermediate step to achieving the ultimate miniaturization of the CSAC. With a total volume of less than 10 cc and power consumption of about 150 mW, the Symmetricom MAC is the smallest, lowest power atomic clock ever. Despite the low power and small size, the short-term frequency stability of the MAC competes favorably with quartz oscillators of comparable size and power. At 100 seconds of integration time, the MAC stability is 4 parts in 10^11, equivalent to gaining or losing 1 second every 10,000 years.

For further reading...

The MAC - A Miniature Atomic Clock. Download Now. 2005: An Ultra-Low-Power Physics Package for a Chip-Scale Atomic Clock. Read Now. 2004: The Chip-Scale Atomic Clock – Low-Power Physics Package. Read Now. 2003: The Chip-Scale Atomic Clock – Recent Development Progress. Read Now. 2002: The Chip-Scale Atomic Clock – Coherent Population Trapping vs. Conventional Interrogation. Read Now. 2004: Time on a Chip: The Incredible Shrinking Atomic Clock, New York Times. Read Now.