A 334-to-348-GHz 7×2 Radiator Array with Coupled-Line-Based Mode-Decoupling Harmonic Enhancement and Chip-to-Waveguide Interface Achieving 30-dBm EIRP

Interest in THz bands continues to grow due to the numerous promising applications, including imaging, sensing and wireless communications. Recent research has showcased the feasibility of silicon-based signal sources and radiators operating beyond 300 GHz [1]–[6]. However, the radiated power levels typically remain significantly below 1 mW and realizing a substantial breakthrough in the EIRP remains an on-going challenge. A primary factor at the circuit level is the low power efficiency in signal generation, though advancements are being made through the exploration of various active devices [1] and the proposition of circuit topologies [2]. As a result, integrating multiple elements into an array at the system level becomes a prevalent strategy for EIRP boosting. This approach, however, leads to a linear increase in power consumption and chip area, and a maximum array size is imposed by constraints related to heat dissipation and manufacturing yield. Moreover, the poor efficiency and the limited aperture of on-chip antennas exacerbates the difficulty in reaching a high EIRP. While the use of off-chip antennas could potentially provide a much higher gain, it also introduces additional complexities, such as the signal connectivity and system packaging issues [1], [4], [6]. This paper presents a 14-element radiator array that features improved power efficiency for each oscillating element and incorporates a chip-to-waveguide assembly to enable high-gain hybrid antenna systems.