Simulation, Modeling and Implementation of an Ultra-Low Phase Noise X-band Frequency Synthesizer
One of the most important components in telecommunication systems and radar activities are frequency synthesizers. Among the important parameters of a frequency synthesizer are phase noise, frequency resolution, programming speed, scanning rate and spur level in the output spectrum of the system. Typically, it is not possible for a frequency synthesizer to reach all of these parameters simultaneously. In other words, there are trade-offs between desired parameters. Among the structures of frequency synthesizers that can be used to achieve the optimal point for these parameters are multi-loop phase lock loop. In this paper, by presenting the noise model of different elements of a frequency synthesizer, simulations related to the achievable phase noise for a sample synthesizer in the X band are presented and finally the results of implementation of a sample synthesizer are presented.
 E. Drucker, "Techniques for Improving Noise and Spurious in PLLs", Microwave Journal, May 2012.
 K. Song, J. Lee, “Frequency Synthesizer Using Dual Offset Mixing for Low Phase Noise and Narrow Resolution", International Frequency Control Symposium and Exposition, 2006.