Introduction

Fueled by data-intensive applications and global connectivity demands, telecommunication is experiencing a rapid shift. To address the exponential data rate needs of future mobile networks (6G and beyond), the sub-THz (100–300 GHz) and THz (0.3–3 THz) bands hold immense promise. These bands offer vast untapped bandwidths for ultra-high data rates and transformative applications. CMOS technology emerges as an attractive solution for (sub-)THz transceiver ICs due to its established large-scale, low-cost production and potential for digital integration. However, significant challenges exist at these high frequencies. This chapter explores the historical context of telecommunication, delves into the benefits and drawbacks of sub-THz and THz communication, and examines the potential of CMOS for cost-effective, integrated (sub-)THz transceivers, paving the way for widespread adoption in future networks.