Catalog

10 MHz Low Close-In Phase Noise with Stabilized PPS

NR6720-O/G/A6

The NR6720-O/G/A6 features extremely low frequency jitter despite being GNSS-locked. GNSS-locking brings a long-term stability to an OCXO that is difficult to match. Instead of an accuracy of 50 ppb/year – accuracies of ~E-12 are readily achieved. However, locking an OCXO to the GNSS presents its own set of problems. The timing information from the GNSS is burdened with all the noise one would expect from a RF link – multi-path, reflections, etc. Long-term stability is enhanced frequently at the expense of “close-in” stability. Low frequency components from the RF link are introduced to the OCXO, often degrading the Allan Deviation of the OCXO. The NR6720-O/G/A6 uses a unique crystal and proprietary control loop to minimize “close-in” degradation while securing long-term stability. The unit also features very low PPS pulse-to- pulse jitter. Instead of the +- 10 ns of PPS jitter from the receiver, the PPS stabilizer reduces PPS jitter to under 800 ps.

• Holdover stability of 5 ppb/day,  50ppb/year.
• LVDS port available for either PPS or 10 MHz
• PPS stability option- P-P jitter < 800 ps.
• Locked accuracy <4E-11.
• Available -60 to +60 Vdc in three ranges or AC power adapter
• Concurrent reception of GPS and GLONASS.
• PPS accuracy 15 ns @ 1 sigma
• Secondary channel synthesized frequency.
• Indicators and signals provide GPS/GNSS lock and unit self-test status.
• NMEA available via RS232 port.
• PPS CMOS port can drive 50 Ohm

Typical Phase Noise