Click here to go to our (modest) main page on phase noise
New for November2021. Phase noise is a term used to describe short-term variations in phase, or frequency instability in a signal. For this month we offer two excellent videos to help you understand phase noise. The first video greatly simplifies this topic; it is a five-minute video from Bliley Technologies. Narrator Sean Federico provides a definition of phase noise, and introduces the spectral density graph. Unless you have purchased quartz crystal oscillators, you might never have heard of Bliley. That nameplate is over 90 years old! Founded by Frank Dawson Bliley in 1930, during WWII Bliley Electric had 1500 employees providing crystal oscillators. Read about Bliley history here. and watch the video Crystals go to War on this Microwaves101 page.
What is Phase Noise? by Bliley Technology
The second video, from Rohde and Schwarz, takes a deeper dive into the effects of phase noise, and how it is measured and analyzed. Narrator Paul Denisowski's talk is based on oscillators, the most critical component in generating low phase noise signals at any frequency. All oscillators introduce some level of frequency instability, which only gets worse when you multiply, mix or amplify their output signal. The video focuses on problems that phase noise can create in communications systems such as spectral re-growth and bit errors, unfortunately leaving out the field of radar. The video covers phase noise measurement with spectrum analyzers and phase noise analyzers. Finally, the cross-correlation method used in phase noise analyzers for improving sensitivity is explained.
Understanding Phase noise Fundamentals, by Rhode and Schwarz