Resolution requires Accuracy
Competitive Signal
Generators may offer either high resolution or high accuracy, but
typically do not offer both options in one unit. Even the best and
extremely expensive "high-stability" options in competitive units
typically provide only >10-8 of frequency
accuracy and require regular calibration. What does a high relative
resolution deliver without absolute accuracy? An uncertain frequency at
best.
To provide a solution for
this paradox, the FireFox GPS Disciplined Signal Generators for the
first time provide ultra-precise frequency generation (10µHz default
step size over entire frequency range) with a GPS-derived Atomic Clock
frequency accuracy (<10-12 long term) in
one unit. The FireFox Signal Generator allows any frequency up to
1640MHz to be generated with a typical accuracy of +-5x10-11
(averaged over 30 min.) while simultaneously offering a resolution of
10µHz! As a result of using a specialized GPS timing receiver, the
internal FireFox frequency reference never needs to be calibrated. An
additional major benefit over competitive units is the simultaneous
generation of both Synthesized Analog (RF) and Digital (CMOS/TTL,
LVDS/PECL) outputs. The FireFox Signal Generators are available in two
variants:
The FireFox Desktop
Sweeping Signal Generator is designed to be used in typical laboratory
environments. Output signals range from DC to 1640MHz with a step size
of 10µHz. Outputs are either Continuous Wave (CW) or Swept. Signals
include CMOS, TTL, LVDS, PECL and analog RF sine waves. The RF signal
generator has an adjustable output amplitude ranging from -40dbm to
+10dbm with <+-1dbm accuracy. RF as well as LVDS/PECL signals
can be generated from 2MHz to 1640MHz. The CMOS/TTL output ranges from
DC to 398MHz with 3.3Vpp or 5Vpp. The LVDS, CMOS and RF outputs are
driven in parallel, and may be independently used. Additional outputs
include a GPS driven 1PPS CMOS output synchronized to UTC to
<20ns, a general purpose very low phase-noise 10MHz Frequency
Reference output, and a general purpose 2GHz RF Mixer. The 2GHz Mixer
has a filtered IF output with <3MHz to >350MHz bandwidth.
The FireFox Desktop unit is shipped with a GPS antenna, a USB to RS-232
converter, RS-232 cable, power cable, BNC cable, and a user manual.
The FireFox OEM Module has
identical technical specifications as the FireFox Desktop unit with the
exception that the OEM Module uses an external AC to 12.0V DC power
supply. The FireFox OEM unit is usefull as a dedicated Frequency
reference inside OEM enclosures, or as a remote controlled frequency
source. Frequencies from 10µHz to 1640MHz can be set quickly with 10µHz
resolution (15-Digits) using the built-in LCD and keypad, or via SCPI
commands on the RS232 connector. Settings and calibrations are
automatically stored in non-volatile memory. The FireFox OEM unit is
shipped with a wall-wart 12.0V power supply, a GPS antenna, a USB to
RS-232 converter, RS-232 cable, power cable, BNC cable, and a user
manual.
The FireFox units use an
internal GPS timing receiver that disciplines a high-quality OCXO which
in turn drives a 48-bit Direct Digital Synthesizer (DDS) to achieve
frequency accuracies of typically better than +-5x10-11
when averaged over 30 minutes. Long term accuracy of the internal OCXO
is typically better than 10-12 when averaged
over one day. Using a 48bit DDS allows a step size of 10µHz over the
entire 1640MHz bandwidth.
