Dielectric Loaded Endfire Antennas Using Standard Silicon Technology

This paper presents two endfire on-chip antennas (OCAs) at 140 and 320 GHz using a standard 0.13- $\mu \text{m}$ SiGeBiCMOS technology; quasi-Yagi antenna concept is used with loaded dielectric. In order to eliminate the influence of the low-resistivity silicon substrate, the substrate thickness is chosen as $\sim 84~\mu \text{m}$ (for 140 GHz), and the antenna is mounted on the edge of a metal supporter with the front part ungrounded. The loaded dielectric is designed using the silicon and silicon dioxide (SiO2) layers to improve the gain. The antenna shows the measured impedance bandwidth of >45% at 140 GHz, with the peak gain of 4.1 dBi, and the simulated peak radiation efficiency of 83%. A $1 \times 2$ array at 140 GHz is also designed and implemented; the corresponding measured impedance bandwidth, peak gain, and simulated radiation efficiency are >36%, 7 dBi, and 72%, respectively. With the proposed structure, the OCA at 320 GHz is also designed and fabricated with the substrate thickness of $\sim 34~\mu \text{m}$ . The measured gain of 3.9 dBi and the simulated radiation efficiency of 80% are achieved at 320 GHz, respectively.