Advances in Terahertz CMOS for 6G

Terahertz has recently been attracting attention in communications although it has been mainly focused on the field of non-invasive sensing. In particular, the 300 GHz band, which can be used in the 44 GHz frequency range from 252 GHz to 296 GHz, is expected to be used for ultrahigh-speed wireless communications toward 6G. Traditionally, compound semiconductors and BiCMOS circuits with excellent high-frequency characteristics have been considered advantageous at terahertz (or sub-terahertz), including the 300 GHz band. In this talk, the significance and potential of realizing terahertz communications with CMOS integrated circuits, which have relatively poor high-frequency characteristics, will be discussed. An overview of ultra-wideband wireless communication in the terahertz band, including the 300 GHz band, will be given, and the necessity of a communication system using phased arrays and the significance of using CMOS integrated circuits in this system will be clarified. Finally, a 300 GHz CMOS wireless transceiver capable of transmitting data rates of up to 80 Gb/s will be presented, which can be used as an element of terahertz phased array.