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.