This is a detailed article comparing phase noise measurement techniques and their advantages and disadvantages. You will need to be a member of the Microwave Theory and Techniques society of the IEEE to view the article for free. A purchase option may be available if you are not a member.
Accurate measurement of phase noise is one of the most difficult measurements in all of electrical engineering. The biggest challenge is the huge dynamic range required in most phase noise measurements. There are several methods to measure phase noise, and the right one must be chosen to make the necessary measurements. To make a proper selection from the various methods, it is necessary to know and appreciate the weaknesses and strengths of each of the different techniques because none of these methods is perfect for every situation. This article focuses on key phase noise measurement techniques for oscillators and reviews their advantages and disadvantages.
The article lists a large number of references which may be of interest as well.