Why is the loop bandwidth optimization critical for jitter cleaning?
• Up to the loop bandwidth frequency, the output phase noise (jitter) follows the reference clock phase noise and after the loop bandwidth frequency, the output follows the VCXO phase noise. If the reference clock is cleaner than the VCXO at lower frequencies from the carrier, the higher loop bandwidth is desirable. If, on the other hand, the reference clock is noisier than VCXO, the lower loop bandwidth will help to clean jitter from the reference clock.
