A signal generator for generating multiple phases includes a ring oscillator with at least one first adjustable delay stage and at least one second delay stage being serially arranged, wherein an output of the first delay stage is provided for delivering at least one first output phase and an output of the second delay stage is provided for delivering at least one second output phase, and an adjustment circuit for adjusting the delay of the first adjustable delay stage, wherein the adjustment circuit is provided for adjusting the phase relationship between the first output phase and the second output phase by means of setting a first propagation delay for the first delay stage.