Features
Specifications
Frequencies
Software
FAQs |
Rhino 3 Low-Cost Frequency Source
The
Rhino3™ is a low-cost, portable frequency
source designed for both laboratory and field use where GPS reception
may be unavailable, such as underground, indoors or in large cities.
Once GPS satellites are acquired, Rhino3’s ovenized crystal oscillator
provides absolute accuracy and stability of 1E-9. Rhino3™ includes
an internal Ni-MH battery/fast charging system so it may be used anywhere
(over 1 hour runtime) to provide reference frequencies without loss
of synchronization. The portable unit provides references for 1PPS
PHASE and 10 MHz FREQUENCY measurements and adjustment. Rhino3™ includes
12 VDC input and RS-232 interface to PC but is a self-contained frequency
source that includes push button control and LCD interface.
Rhino3
is a younger brother of the BVS Rubidium Frequency source Rhino2.
The main difference is that Rhino3 is using an ovenized oscillator
and thus is a cheaper device. Both of the devices use GPS to train
their oscillators. This allows achieving an absolute accuracy while
oscillators are locked to GPS. Off course the stability of the Rubidium
oscillator is better than the stability of the ovenized crystal.
Nevertheless after training from GPS the Rhino3 provides IS-97 sufficient
holdover for a couple of hours.
Rhino3 can be used as a frequency reference in the laboratory, providing
3 buffered 10MHz sinewave outputs. However it was primarily designed
for field applications such as real time frequency and phase measurements
and adjustments. These applications are supported by a built-in battery
and the charging system, external 12VDC (vehicular) power supply and
frequency and 1PPS phase inputs. The accuracy of the internal oscillator
allows for a good reference while conducting the measurements. The built-in
display allows monitoring the measurements and doing the adjustments
if necessary in real time. This can be performed even in locations where
there is no power or GPS available for the test equipment. Off course
data logging to a laptop via an RS232 port is also supported.
The processing part of the Rhino3 consists of the PIC18LF6720 and Xilinx
PLD XC95144XL. A functional diagram of the PLD shows three main counters.
One is used to measure the relative phase of the internal ovenized oscillator
and GPS PPS and to perform necessary adjustments to the oscillator frequency
to lock and stay locked to GPS. The phase of the output 1PPS signal is
a moving average of the GPS PPS phase measured over a 20 min interval
after the lock has been achieved. The phase resolution is +/-10ns.
The second counter is used to measure the input frequency. It is gated
by the internal 1PPS signal. The range of the measured frequencies is
limited by the front end chopper’s dynamics and the lengths of
the counter and is up to 20MHZ. In comparison the Rhino-2 because of
a more sophisticated and expensive front end and the processing scheme
can measure frequencies up to 2GHz. The third counter supports phase
measurements. The input 1PPS phase is compared to the internal 1PPS phase.
The resolution of the measurement is +/-10ns. The largest phase difference
measured is 655ns.
 Download Rhino3 data
sheet
Download Rhino3 manual
from the Technical Support section |
