Technical Article: Understanding Phase Noise in Precision Oscillators
A deep dive into phase noise fundamentals and practical oscillator selection criteria for demanding frequency control applications.
Phase noise is one of the most critical specifications for precision oscillators used in telecommunications, radar, and scientific instrumentation. Understanding how to interpret and compare phase noise specifications is essential for selecting the right oscillator for your application.
What is Phase Noise?
Phase noise describes the frequency domain representation of rapid, short-term, random fluctuations in the phase of a waveform. It is typically expressed in dBc/Hz at a given offset frequency from the carrier.
Practical Oscillator Selection Criteria
When selecting an oscillator for a demanding application, consider the following parameters:
- Phase noise floor — critical for close-in and far-from-carrier applications
- Frequency stability — short-term (Allan deviation) and long-term (ageing)
- Temperature coefficient — important for uncontrolled environments
- Supply voltage and power consumption — critical for remote and battery-powered installations
- Output level and waveform — sine, CMOS, LVDS depending on application
Quartzlock Oscillator Portfolio
Our oscillator range covers OCXO, TCXO, VCXO, and GNSS-disciplined standards from 1 MHz to 1 GHz. All models are characterised over temperature and supplied with full test data.