Oscillators - An Introduction

Oscillators are electronic devices which generate a recurring waveform (the resonance frequency). This frequency is a counter to measure time and so is used extensively in clocks as a frequency reference source. Quartz crystal is the most widely regarded material to use in oscillator circuits because of its stability.

Oscillators fulfil a vital role as they are disciplined by the instrument's primary time reference source so that in the event of a signal interruption a properly calibrated time reference signal is maintained.

Oscillator Grades

TCXO - Temperature Compensated Crystal Oscillator

Temperature can affect oscillator frequency variations leading to inaccuracies. The TCXO uses an electronic circuit to compensate for changes in ambient temperature and so benefits from a higher level of stability than a standard quartz crystal oscillator.

OCXO - Oven Controlled Crystal Oscillator

The cystal is enclosed in a temperature-controlled chamber (oven) which results in a very stable environment, and consequenctly a very stable frequency.

Rubidium Oscillators

Rubidium oscillators make use of the atomic resonance of Rubidium (Rb87) to control the frequency of a quartz crystal oscillator and results in an extremely high level of stability.

Caesium (or Cesium) Oscillators

Caesium is the primary standard for time and frequency measurements used in atomic clocks because the resonance is exactly in line with the definition of a second as defined by the International System of Units (SI).