0

I've recently designed an oscillator for a frequency range of 80 - 100MHz. I would like to analyse the phase noise of the oscillator. From my knowledge of "phase noise", it is the power of a frequency, given a certain offset from the carrier, subtracted from the power of the carrier itself.

I am also trying to look at the phase noise across the entire tuning range, for a fixed offset, instead of different offsets which is usually the convention.

Given the theory above, is it applicable if I choose a singular offset of 200 kHz? The reason I ask is, it seems common to choose an offset of 1 MHz, which is what I've seen in literature. However, I'm yet to see information stating that an offset other than each decade, would be incorrect.

Suva23
  • 33
  • 5
  • The correct offset is the one that matters to you. To 'analyse the phase noise', you need all offsets, at least all between two limiting frequencies like 10 Hz and 10 MHz. You can choose a single offset of 200k if you like, but it won't tell you anything about the phase noise at 1 kHz, or the noise floor, or very close in. Why do you want to know the phase noise? The answer to that should inform what frequency offsets you need. Have a look at manufacturers of oscillators, and see what offsets they quote phase noise at. – Neil_UK Feb 19 '23 at 20:33

0 Answers0