Modeling of Spectral Characteristics of the Links of Phase Distortions Autocompensator of Direct Digital Synthesizers

The article presents a mathematical modeling of the spectral characteristics of the links of the path of generation of the control signal of the phase distortion autocompensator of digital computational synthesizers. The sources of distortion of the output signal of these devices are shown, which have a significant impact on their spectral purity and lead to undesirable phase modulation of the useful signal. The possibility of using automatic compensation to reduce the phase distortion of the output signal of direct digital synthesizers is considered. The functioning of the control signal generation of the autocompensator presupposes the isolation and processing of phase noise of the output signal. A model of the output signal of a direct digital synthesizer is obtained, taking into account parasitic phase modulation and distortions caused by truncation of the phase code, amplitude quantization and the nonlinearity of the converter from digital to analog form. The results of mathematical modeling confirm the effectiveness of the proposed algorithm for detecting phase impurities of the output signal of a direct digital synthesizer and reflect the functioning of the path forming the control signal of the phase distortion auto-compensator.