High-Power, Efficient THz Generation in Silicon for Broadband Sensing and Wireless Communication

The THz band, ranging from 0.1 - 10 THz, has largely remained untapped due to challenges in the THz generation. This band occupies a unique position in the electromagnetic spectrum between RF and optical frequencies and can enable several applications such as high-speed communication, imaging, radar, and spectroscopy. However, THz frequencies lie beyond the fmax of silicon technologies, making direct THz generation unfeasible. This paper is an overview of approaches for efficient high-power THz generation in silicon by utilizing the reverse recovery of PIN diodes. We review the design of a THz pulse radiator and a Continuous wave (CW) radiator fabricated using GlobalFoundries 90 nm SiGe BiCMOS process. THz applications such as imaging, vibration sensing, gas spectroscopy, and communication, are demonstrated. THz channel characterization using a pulse radiator is also presented. We conclude the paper with a discussion on the potential for silicon-based THz generation beyond 1 THz.