Sub-THz beam-forming using near-field coupling of Distributed Active Radiator arrays

The paper demonstrates Distributed Active Radiator (DAR) arrays as a novel way of beam-forming at sub-THz frequencies in CMOS. Near-field coupling is shown to be a scalable method for mutually locking multiple DARs to beam-form and generate high EIRP. As proofs of concept, 2×1 and 2×2 arrays of DARs, mutually synchronized through near-field coupling, are implemented in 65nm bulk CMOS. The paper also shows beam-forming near 200GHz for the 2×2 array with broadside EIRP of −1.9 dBm, total radiated power of 54 µW and beam-scanning range for approximately ± 30° in each of the two orthogonal directions in 2D space.