Abstract : A general procedure, based on the SemiDefinite Re-laxation (SDR) technique, is presented to solve efficiently a wide range of difficult (because non-convex) array synthesis problems. This powerful approximation technique is easy to implement and the so-approximated problem can then be efficiently solved using off-the-shelf numerical routines. Examples of shaped beam and reconfigurable array synthesis are shown to illustrate the potentialities of the proposed approach.