Airbus Defence and Space


SpHARO quartz oscillator

The SpHARO (Space High Accuracy Reference Oscillator) is a miniature quartz-controlled oscillator for space and airborne applications. The oscillator provides a mission frequency control of less than ±1ppm, plus excellent medium and short-term stability and low phase noise.

This is an oven-controlled quartz crystal oscillator (OCXO) using a “direct-heated” resonator, fabricated from AIRBUS Group-Airbus Defence and Space’s High Purity Quartz. This material is the purest and most highly qualified quartz in the world and provides the SpHARO resonator with excellent intrinsic radiation tolerance. The oscillator achieves good short-term and long-term stability as a result of rigorous resonator fabrication process controls and proprietary resonator.

Features / technical details

Main Features

  • Precision 5th-overtone SC-cut resonator using High Purity Quartz
  • Direct-heated resonator gives very low power and fast warm-up
  • Low noise analogue RF and precision DC control circuitry in surface-mount format
  • Uses Airbus Defence and Space-grown High Purity Quartz for radiation tolerance
  • Extremely light and compact for a precision OCXO


Frequency 10 MHz
Stability (all causes) <±5x10-7 (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 <5x10-11 (1s – 100s)
Warm-up <±5x10-7 in 5 minutes (-30°C)
Output 10 dBm sine
Power consumption 300 mW (steady state, 25C)
Supply 10-15 volts
Size 50 x 35 x 15mm
Weight 30 grams


  • Extremely small and light
  • Radiation tolerant
  • Mechanically robust – to withstand satellite launch vibration and solar panel deployment etc.


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


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


The SpHARO can be used as the master frequency reference in spaceborne applications where high frequency stability is required together with very low mass, and size and power consumption.

Reference customers

  • Radarsat-2
  • Core Radar