450-GHz On-Chip Dual-Patch Antennas with Expanded Bandwidth and Filtering Response

This article presents two 450-GHz on-chip dual-patch antennas with expanded bandwidth and filtering response. Traditional on-chip patch antennas use the bottommost metal layer (M1) as the ground, securing a high degree of isolation from the active region. However, this method considerably confines the antenna profile, substantially limiting the antenna bandwidth. In this paper, a dual-patch structure is proposed to overcome this challenge. Remarkably, even under an extremely low profile of 0.013 λ0, the designed antennas accomplish an impedance bandwidth exceeding 15%. In addition, the intrinsic characteristics of the dual-patch structure generate multiple radiation nulls, paving the way for the design of a filtering antenna built upon this structure. Two antennas with and without filtering were fabricated using 65-nm CMOS technology for empirical validation. Measurement shows that the gain-optimized antenna reaches an impedance bandwidth of 15.5% and a peak gain of 3.1 dBi. Meanwhile, the filtering antenna achieves an impedance bandwidth of 15.3% and a maximum gain of 1.6 dBi. The filtering antenna demonstrates good stopband suppression and distinctive radiation nulls. Those unique features make the proposed antennas highly suitable for future fully integrated wireless systems in applications such as 6G (the sixth generation) networks, short-range high-data-rate communication, and terahertz detection.