Description: The article describes the operation of a combined synthesizer, on the basis of a direct digital synthesizer (DDS) and a tworing phase locked loop system (PLL). Expression is got for the model of spectral density of power of a phase noise of a combined synthesizer is gained. Results of modeling of noise performances of a combined synthesizer for various target frequencies (3 - 11 GHz) are resulted.
Keywords:
combined synthesizer, PLL, DDS, noise characteristics, the phase noise