In this contribution we present a custom test-bench capable of delivering multi-path mm-wave signals with amplitude and phase control to an on-wafer environment. The setup employs direct IQ up-conversion in the 7.5GHz to 10GHz band, with high resolution DACs to modulate both amplitude and phases of n coherent LO signals. Signal amplification followed by frequency multiplication generates mm-wave signals in the 30 to 40GHz range. An amplitude pre-distortion technique, to level the IQ mixer output power versus phase angle, and a calibration technique are developed to achieve accurate amplitude and phase control between the signals at the wafer probe-tip level.