The book brings together the following issues: • Theory of deterministic, random and discrete signals reproducible in oscillatory systems of generators; • Generation of periodic signals with a specified spectrum, harmonic distortion factor and random signals with specified probability density function and spectral density; • Synthesis of oscillatory system structures; • Analysis of oscillatory systems with non-linear elements and oscillation amplitude stabilization systems; • It considers the conditions and criteria of steady-state modes in signal generators on active four-pole elements with unidirectional and bidirectional transmission of signals and on two-pole elements; analogues of Barkhausen criteria; • Optimization of oscillatory system structures by harmonic distortion level, minimization of a frequency error and set-up time of the steady state mode; • Theory of construction of random signal generators; • Construction of discrete and digital signal generators; • Practical design of main units of generators; • Practical block diagrams of both analog and digital signal generators.