Direct digital synthesis of complex broadband signals

One of the main functional blocks of modern radio systems is frequency synthesis systems. Therefore, the problem of forming high-stable frequency spectrum is urgent during the development of many radio systems. Such advantages of DDS as technological effectiveness, reliability, resistance to destabilizers, extremely small time of frequency switching during frequency tuning, phase discontinuity of formed oscillations, the capability of forming complex broadband signals, the possibility of complete microminiaturization, good repeatability of parameters during the replication allow improving the engineering-and-economical performance of many radio engineering systems considerably. The purpose of the work is to extend functional capabilities of direct digital synthesizers and digital frequency synthesizers, increase their operation speed, improve the "spectral purity" of formed signals and decrease the level of amplitude and phase noises. Research methods. While solving the set tasks, the methods of the signal theory, number theory, probability theory and mathematical statistics as well as mathematical modeling, computer simulation and experimental research were used in the work. Results. In the direct digital synthesizer of frequency-modulated signals, the signal with V-shaped frequency modulation is formed. It is used in radiolocation for the Doppler frequency measurement. The direct digital synthesizer of phase-modulated signals can be used when designing transmitter modulators with digital control of frequency and phase of synthesized oscillations.