European Space Agency

Quartz Oscillator Developments

AddToAny

Objectives

The objectives of the project were to develop four quartz crystal oscillators:

  • OCXO-U: an ultra-stable OCXO, based on Airbus existing “FOAMO” product, for e.g. master oscillator applications
  • OCXO-S: a mid range OCXO for the most demanding frequency converter and receiver applications, beacons and less demanding master oscillators
  • TCXO: a TCXO for a wide range of applications including frequency converters and receivers and transponders
  • VCXO: a VCXO for a range of phase locked-loop and other clock applications

An EQM of each oscillator was manufactured and qualification test programme completed. 

A High Purity Quartz stone grown by Astrium


click for larger image

Challenges

A top-level issue that is addressed by the project is to maintain a European supply of quartz crystal oscillators for the space market – Astrium has a significant strength in having its own quartz growth facility. Design for Manufacture and Test are key elements of the project so as to allow faster and cheaper assembly, alignment and test. In addition, all oscillators have been designed so as to withstand high shock levels, which are continuing to increase as spacecrafts get larger.

Benefits

Following development to EQM stage and qualification, Airbus are able to offer a range of quartz oscillators to the space market that have improved performance over competitors and will be ITAR free. In addition, Airbus-grown High Purity Quartz (generally considered to be the purest in the world) will be used to give highly radiation-resistant devices. This will maintain Airbus European source for quartz suitable for space applications.

Features

The OCXO-U is an oven-controlled crystal oscillator using a fifth-overtone SC-cut quartz at a frequency of nominally 10MHz. This is the key element in determining frequency stability. Special processing ensures extremely low ageing and the use of Airbus High Purity Quartz gives very low radiation sensitivity. The main developments in the OCXO-U project are making the oscillator able to survive higher shock levels and significantly reducing the assembly and alignment time. The oscillator has been designed to have a size of 51 x 51 x 52mm and is shown in the figure below, mounted on a test plate (the OCXO-U can be supplied for PCB mount or chassis mount, using a plate similar to that shown).


click for larger image

The OCXO-S shown below uses a higher-frequency SC-cut resonator at 100MHz. The smaller resonator results in slightly higher ageing than the OCXO-U but the resonator itself will be able to withstand higher shock levels. The oscillator has a package of dimensions 26 x 26 x 18mm.


click for larger image

The TCXO uses an AT-cut resonator to produce output frequencies between 40MHz and 150MHz (EQM frequency is 120MHz). An analogue compensation method is used. The package is common with the OCXO-S.

The VCXO also uses an AT-cut resonator and the common package with the OCXO-S.  The use of an internal frequency multiplier allows frequencies of 40MHz to 150MHz to be obtained (EQM frequency is 112.5MHz).

Plan

Kick-off May 2012
PDR Jan 2013
CDR Sep 2013
Final Report/Review Sep 2015

KEY ISSUES

A top-level issue that is addressed by the project is to maintain a European supply of quartz crystal oscillators for the space market – Airbus has a significant strength in having its own quartz growth facility. Design for Manufacture and Test are key elements of the project so as to allow faster and cheaper assembly, alignment and test. In addition, all oscillators have been designed so as to withstand high shock levels, which are continuing to increase as spacecrafts get larger.

Current status

Completed.  Final Review was held in Sep 2015.

Contacts

Status date

Wednesday, May 25, 2016 - 08:36