Airbus Defence and Space


FOAMO Quartz Ultra-Stable Oscillator (USO)

Miniature Master Oscillator

The FOAMO (Foam-insulated Master Oscillator) is a miniature ultra-stable quartz-controlled master oscillator for space applications. The oscillator provides a mission frequency control of less than ±1pp107, coupled with excellent medium and short-term stability and low phase noise. This oven-controlled quartz crystal oscillator (OCXO) uses a high-overtone SC-cut resonator fabricated from Airbus Defence and Space-grown High Purity Quartz. This material is the purest and most highly qualified quartz in the world and provides the FOAMO resonator with excellent intrinsic radiation tolerance.

Features / technical details

Main Features

  • Excellent frequency stability, combined with low mass, size and power consumption
  • Precision 5th-overtone SC-cut quartz resonator
  • Uses Airbus Defence and Space-grown High Purity Quartz for radiation tolerance
  • Low noise analogue RF and precision DC control circuitry in surface-mount format
  • Advanced thermal management


Frequency 10 MHz – or custom, e.g. 5-15 MHz
Stability (all causes) <±1x10-7 (15 years)
Ageing <±1x10-11/day
Frequency/temperature <±1x10-11/°C
Phase noise  
  1Hz -110 dB/Hz
  10Hz -140 dB/Hz
  100Hz -150 dB/Hz
  >1kHz -155 dB/Hz
Allan variance <2x10-12 (1s – 100s)
Warm-up Less than ±1x10-8 in 10 minutes (-30°C)
Output 10 dBm sine
Power consumption 2 W (steady state, 25°C)
Supply 10-15 volts
Size 84 x 54 x 42 mm
Weight 80-220grams, depending on configuration



  • Very light and compact for a quartz USO
  • Radiation tolerant – total dose and prompt radiation
  • Mechanically robust – to withstand launch vibration and solar panel deployment


  • Co-axial voltage supply for EMC, 10-15 V
  • EFC suitable for telecommand
  • Can be phase-locked, e.g. to an atomic standard


  • Operating temperature: -30°C to +70°C
  • Radiation tolerance: 100krad
  • G-sensitivity: <1x10-9/g


The FOAMO ultra-stable oscillator is designed for use as the master frequency reference in spaceborne applications where high frequency stability is required together with low mass, power and size.

Reference customers

  • Inmarsat-4
  • Skynet-5
  • Anik-F1R
  • Sirius-V