Broadband 400 GHz On-Chip Antenna With a Metastructured Ground Plane and Dielectric Resonator

The analysis, modeling, design, simulation, and experimental evaluation of a 400 GHz on-chip antenna is presented, with a novel combination of metastructures, a microstrip patch, a quartz-based dielectric resonator, and a diamond-based antireflex layer—all integrated on a 35 nm InGaAs metamorphic high-electron-mobility transistor (mHEMT) technology. The said combination represents a first-time implementation for all submillimeter-wave-capable semiconductor technologies. Circumventing a substrate-thickness limitation of
$4.98 \mu \text{m}$
, a state-of-the-art broadband, efficient, and to-the-broadside radiating on-chip antenna solution is realized. It achieves a measured impedance bandwidth of 100 GHz, 25.6%, spanning from 340 to 440 GHz. A consistent pattern bandwidth of 75 GHz is recorded, with an efficiency of 50%–66% and a directivity of up to 10.4 dBi—or 27 dBi, with the utilization of a polypropylene-based dielectric lens. The theoretical analysis of the proposed on-chip antenna is presented, and two modeling approaches are shown and compared. Between the analytical and the 3-D electromagnetic (EM) model, the latter is chosen as it offers greater precision in defining the metastructure unit cell and enables the inclusion of the remaining components of the proposed antenna setup. The measured reflection coefficient and far-field patterns are compared to simulations via the utilized model, and a strong agreement is observed. These far-field patterns are acquired with the on-chip antenna inserted within a broadband 400 GHz transmitter submillimeter-wave monolithic integrated circuit, processed on the 35 nm mHEMT technology.