High-stability frequency reference rivals atomic clock, provides GPS holdover

January 23, 2015 // By Graham Prophet
The IQFR-100 high precision GPS frequency reference from IQD delivers a frequency accuracy of better than ±1E-12 after a period of 24-hours stable satellite signal lock. This is similar to the stability levels of much more expensive caesium atomic clocks, the company says.

Intended primarily for use in applications such as communications systems, power grid references, national defence equipment and smart metering, the system is designed to operate in conjunction with either a GPS or Compass satellite signal. This allows the frequency reference to maintain a high stability in the event of signal failure by virtue of the high performance internal oven controlled crystal oscillator. In the event of a loss of signal, the unit maintains an accuracy of better than 5E-11 until restoration of lock due to the internal reference oscillator.

Housed in a standard 1U rack mountable cabinet, the IQFR-100 provides for a number of output interfaces. This includes two 10 MHz Square wave outputs (accuracy better than 1E-12); two square wave outputs at 2.048 MHz, again with an accuracy of better than 1E-12; and two 1PPS impulse outputs with a holdover specification of less than or equal to 1.5 µsec in the event of the loss of the satellite signal.

Consuming under 7W whilst operating from a standard 220 VAC supply line, the IQFR-100 has an operating temperature range of -20 to +60C. In the event of a power outage failure at the mains source, an internally rechargeable battery switches in to maintain system stability performance prior to restoration of the supply. The various outputs are presented via back panel BNC connectors in addition to a standard aerial connector. Various front panel LED lights indicate lock of the satellite signal as well as system fault conditions.

IQD; www.iqdfrequencyproducts.com