Modeling the noise properties of hybrid frequency synthesizers with automatic compensation of phase noise of DDS

Held modeling of noise properties of the three schemes of hybrid frequency synthesizers on the basis of PLL and direct digital synthesizer with automatic compensation of phase noise. Interference suppression of hybrid synthesizers performed by isolating the law of parasitic phase deviation of the output signal of the digital synthesizer and changing the modulating voltage of controlled oscillator of the PLL in accordance with the law of selected phase deviation. The graphs power spectral density of phase noise of individual blocks of hybrid synthesizers are drawn and estimated degree of suppression of phase noise in the output signal of the analyzed devices.