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Specifying Rubidium Oscillators
Questions Covered
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What is a rubidium oscillator?
How does a rubidium oscillator work?
Why use a rubidium clock?
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Our IQRB-1 rubidium oscillator is a sub-
miniature atomic clock exhibiting
rubidium oscillator performance in a
65cc OCXO style package at a standard
frequency of 10MHz.
It offers 100 times less drift than an
OCXO and has a short term stability of
0.008ppb/s at 100s, providing
significant improvements in
performance over OCXOs.
What is a rubidium oscillator?
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It is a type of “atomic clock”
These clocks are the most accurate
time standards known and are used as
time distribution services to control
things such as:
telecommunications infrastructure
TV broadcasts
global navigation satellite systems (GPS)
The part of the rubidium oscillator
which is responsible for providing the
output signal is actually a quartz crystal
oscillator (OCXO).
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The rubidium “physics-package” and its
associated control circuitry provides
the timing accuracy to control the
OCXO frequency.
In quartz oscillators, the device is
adjusted to frequency when it is made
but its frequency is never generally
checked again. Over time, its frequency
changes slightly, making the clock run
fast or slow.
The rubidium section of the oscillator
continually checks the frequency of the
quartz oscillator and adjusts it back
onto frequency.
How does a rubidium oscillator work?
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Simplistically, it’s the behaviour and
monitoring of rubidium particles at an
atomic level whereby this behaviour is
subsequently fed electronically to the
control input of a crystal oscillator so
that it’s output frequency can be
adjusted.
Rubidium is usually in the form of a soft
silvery metallic element.
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By using the rubidium as a gas held in a
glass cell and exposing it to light of the
correct frequency, its absorption
changes when the surrounding
microwave frequency is just right.
This absorption rate can be measured
and thus forms the basis of a very stable
clock.
Why use a rubidium clock?
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The advantage of a rubidium clock over
the other atomic devices such as
caesium clocks is that rubidium clocks
are much lower cost, small and portable.
More information can be found on our
website.
Standing out from the crowd
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