Abstract: A method is provided for insuring phase-coherency of a sinusoidal signal when changes occur in the signal's frequency. The method may include generation of a phase word that may be used for accessing entries in a relatively small Sin(x) and Cos(x) Look-Up-Tables (LUTs), which may represent values of a sinusoidal signal. The Cos(x) LUT may be used for generating a phase-related error data that may be added to a corresponding entry of the Sin(x) LUT to derive a value that is translated by a digital-to-analog into a corresponding analog value of the generated sinusoidal signal. The phase word may be obtained by multiplying a time word with a frequency word. The frequency word may control the signal's frequency and the phase word may maintain phase coherency. A signal generator is also provided, which utilizes the method.