Method and circuit arrangement for generating a periodic electric signal with controllable phase

Abstract

The invention relates to the generation of an electric output signal with a specified frequency and a phase (P) dependent upon a control signal (x) by means of weighted superposition of several input signals (s, s, s, s), which have the specified frequency but different input signals phases, whereby the weighted superposition is applied to a parallel switching of adjustable transconductance stages which are each adjusted by the control signal (x) and to each of which one of the input signals (s, s, s, s) is supplied. In order to be able to use this so-called phase interpolation to meet higher linearity requirements, the invention provides that for the generation of the output signal with a phase which lies between a first input signal phase (0°) of a first input signal (s) and a second input signal phase (120°) of a second input signal (s) which second phase is larger by a phase difference (120°), the first input signal (s) and the second input signal (s) and two further input signals (s, sand S, sresp.) are superimposed in a weighted fashion, whereby the two further input signals (s, sand S, sresp.) have phases different by the phase difference (120°) and are phase-shifted by one half (60°) of the phase difference with regard to the first and second input signals (s, s).