Sub-THz Reflectarrays: An Alternative Architecture for Enhanced Array Scaling with 3D Heterogeneous Integration for DoD ELGAR Use Cases

The G-band of the electromagnetic spectrum (110-300GHz) comprises an attractive and underutilized portion of the spectrum, with a myriad of defense applications across communications and sensing including Space Situational Awareness (SSA), concealed weapons detection, sensing in Degraded Visual Environments (DVE), and high-bandwidth communication in terrestrial, airborne and space platforms. The challenges with building G-band antenna arrays are well documented and include difficulties at the device and system levels, as well as packaging and thermal challenges. These are exacerbated by the small ?/2 footprint needed for dense array operation, as well as sensitivity to mechanical and fabrication tolerances and associated parasitics such as inductance and capacitance. On the packaging side, traditional approaches such as wirebonding and flip-chip packaging lead to severe performance degradation due to additional parasitics and tolerances in fabrication and assembly. Cambridge Terahertz proposes an alternative sub-THz phased array architecture incorporating 3DHI as a path to enhance the capabilities envisioned by ELGAR.