Tag: disciplined oscillator

Viavi introduces GNSS-disciplined oscillator for precision timing in low SWaP platforms
Viavi Solutions has launched the µPNT GDO-1000, a GNSS-disciplined oscillator built in the M.2 B-key form factor, suitable for low size, weight and power (SWaP) platforms.

Measuring 22 x 42 mm (the size of a postage stamp) and weighing less than 4 grams, the GDO-1000 is designed for platforms requiring accurate timing in places where traditional timing modules do not fit or are too power-hungry, including defense and airborne platforms, unmanned systems, data center cards, and communications equipment.

The µPNT GDO-1000 addresses these challenges through a combination of capabilities:
- Dual-frequency L1/L5 GNSS reception with microsecond-class 24-hour holdover enables precise, resilient timing in compromised conditions.
- The M.2 B-key form factor drops into modern compute platforms, time appliance cards, and embedded systems without custom mechanical design, drawing approximately half a watt.
- Patented AI and ML algorithms developed by the Jackson Labs team, now part of VIAVI, predict and compensate for oscillator behavior across environmental conditions
- The microelectro-mechanical systems (MEMS) oscillator delivers better thermal stability across the full military temperature range than traditional quartz oven-controlled crystal oscillators (OCXOs), with sustained phase noise and Allan Deviation performance under vibration and shock
- It accepts an external 1PPS input, allowing it to be disciplined by M-code GPS, alternative navigation sources, or other external references without hardware modification
- Multiple 1PPS and low-phase-noise 10MHz coaxial inputs and outputs for system integration flexibility, despite its miniature size.
The GDO-1000 will be on display by Viavi at booth 407 during the 2026 Joint Navigation Conference, taking place June 1-4 at the Northern Kentucky Convention Center. As part of the event technical program, Lisa Perdue and Nino De Falcis of Viavi will speak on a “New Cesium-Less ePRTC Solution to Provide Timing for Homeland Critical Infrastructure.”
June 1, 2026
Portable Time-Loader ready for field deployment

Image: Focus Telecom

Focus Telecom has introduced a new timing product for defense and mission-critical applications, the Time-Loader.

The Time-Loader can be deployed in environments where GNSS signals are denied or disrupted, to support any ground, naval and airborne system that needs real time of day (TOD) and 1PPS external synchronization aligned to UTC or GNSS.

In this emerging era of rapid tactical deployment of defense systems, communications intelligence, missile defense systems, radar/electro-optical sensors and UAS batteries in the field are often in GNSS-denied or jammed environments. This situation creates challenges for access to real time and accurate time of day.

To solve this problem, the Time-Loader generates a GPS L1 C/A code RF output as if the signal were coming from a live-sky GPS antenna. It provides full-constellation GPS output and is compatible with external GNSS receivers. It encodes times with nanosecond accuracy for GPS timing receivers.

The Time-Loader’s GPS-disciplined oscillator (GPSDO) is the Microsemi MAC-SA53/55, which provides excellent UTC accuracy with outstanding hold-over rubidium clock performance.

The Time-Loader is the size of a suitcase, hand-carried and easily deployed. It activates quickly from a cold start or when sensors are deployed for the first time.

Included in the Time-Loader is a self-contained, miniature GPS simulator that provides real-time extremely accurate signals. The 18-channel full-constellation simulator stores location/time/date data in internal memory and stores complex vector data to simulate dynamic scenarios. The simulator also can be used to transcode NMEA or SCPI position/velocity/time (PVT) data into GPS RF signals.

Learn more about the Time-Loader.

August 8, 2022
Furuno to launch single-band GNSS receivers for 5G

Furuno Electric Co. Ltd., based in Nishinomiya, Japan, has developed the GT-88 timing module and GF-8801/02/03/04/05 disciplined oscillator for users who require UTC time-synchronized signals to meet the new 5G requirements.

They provide UTC time-synchronized timing signals (1 PPS/10 MHz) by receiving GNSS satellite signals. Achieved stability is better than that of an atomic clock, including a rubidium.

Photo: Furuno

The GT/GF-88 series includes a brand-new algorithm, named Dynamic Satellite Selection, that provides outstanding multipath mitigation, especially in urban canyon environments, the company said. The algorithm was developed by Nippon Telegraph and Telephone Corporation (NTT) based in Tokyo, Japan.

Extremely high stability of 4.5 ns (1 sigma) is obtained, only requiring reception of the L1 band (1575.42 MHz) frequency GNSS satellites. It was achieved by improving advanced position estimation algorithms and optimizing position calculation among several different GNSS satellite constellations. It allows users to achieve 5G-required performance without any changes to existing single-band GNSS antennas.

It incorporates the Dynamic Satellite Selection, an advanced multipath mitigation algorithm developed by NTT. Normally typical time synchronization performance deteriorates in urban canyon environments by the effect of multipath. The Dynamic Satellite Selection reduces this time error by one-fifth. This provides more flexibility when installing GNSS antennas. Consequently, the GT/GF-88 series now permits GNSS antennas to be mounted on walls, windows of tall buildings and other difficult reception environments.

The GT/GF-88 series continues to support GPS, GLONASS and QZSS satellite constellations, and now adds Galileo support. As the total number of satellites available increases, operational stability also increases.

March 25, 2019