Tackling Challenges in 3-D Heterogeneous Integrated (3DHI) Phased Arrays From W-Band Through G-Band

In this talk, highly efficient and dense 3DHI G-band (220GHz) phased arrays developed under the ELGAR program will be presented. Under ELGAR, HRL’s GaN MMICs produce 1–3W/cm² power density, while 3D integration techniques featuring copper micro-pillar technology produced a highly efficient 3DHI-stacked platform targeting 3DHI G-band arrays for next-generation communication and radar systems. The talk will also present updates on our advanced T3.5 40nm GaN HEMT. These mm-wave HEMTs demonstrate W-band device PAE of >55% and yielded a G-band PA MMIC with a measured power added efficiency (PAE) of 18%. Next, W-band device performance, demonstrating state-of-the-art noise figure and efficiency, will be presented. Under the DARPA NGMM, HRL is leading the development of GaN-based W-band phased array prototypes. This includes a 4×4 unit-cell test vehicle targeting 3DHI tiled W-band arrays. The three-tier 3D stack incorporates an antenna on glass, GaN-on-SiC MMICs, a silicon interposer, and a silicon Beam Forming Integrated Circuit (BFIC). The latest results, including GaN MMIC and 3DHI interconnect characterization, will be shared.