We describe the development of MMW SCUBA, an 18–50GHz, dual-polarized, 3D chip stacked scalable phased array antenna with element-level digital beam-forming. Heterogeneous integration of gallium arsenide (GaAs), silicon and silicon germanium (SiGe) devices with 3D printed antenna radiators form the array assembly and convert elemental beam form digits to multiple pointed beams in free space. This new development enables element-level digital beam-forming (eDBF) for massive multi-beam operation enhancing performance of future sensors and communication systems. Details on the fabrication and integration of this assembly and results from an array prototype recently fabricated are discussed. This research was developed with funding from the Defense Advanced Research Projects Agency (DARPA).