Distributed active radiation: Terahertz power-generation and beam-steering in CMOS

Silicon technology can potentially create low-cost, integrated solutions at Terahertz frequency ranges. However, there are significant challenges in generating sufficient power at these frequency ranges with devices operating near or above f_max and further radiating it directly from the chip with integrated beam-control. In this paper, we review some of our work where we propose a true circuit-electromagnetics co-design approach which removes the artificial partitions among the different levels of abstraction in a conventional system design methodology. In the proposed inverse design approach, we start with the desired radiated THz field and aim to formulate metal surface-currents that could generate such a patthern. We then aim to synthesize the current configuration using a judicious combination of actives and passive on chip. This holistic approach led to the conceptual evolution of Distributed Active Radiator. As a proof-of-concept, we demonstrate the first integrated THz phase-darray in CMOS with a 4×4 array of DARs generating nearly 10 dBm Effective-isotropic-radiated-power at 280 GHz and digitally controlled beam-scanning covering more than 800 in 2D space.