A plurality of RF power signals have the same RF frequency as a reference RF signal and are coupled to respective RF connection points on an electrode of a plasma chamber. At least three of the RF connection points are not collinear. At least two of the RF power signals have time-varying phase offsets relative to the reference RF signal that are distinct functions of time. Such time-varying phase offsets can produce a spatial distribution of plasma in the plasma chamber having better time-averaged uniformity than the uniformity of the spatial distribution at any instant in time.