Modern integrated circuit technology has enabled a lot of applications in the RF, mm-wave, and sub- THz frequency range at a low cost and in a small form factor in emerging areas such as wireless communication and radar-based sensing. In this presentation, key challenges in RF, mm-wave, and sub-THz circuit design for next-generation high data rate wireless communication systems and high- resolution radars will be discussed. To address the demand for high performance in these systems, it is becoming increasingly important to take a multidisciplinary approach such as digitally assisted RF circuits and heterogeneous co-integration of III-V and CMOS technologies. The power amplifier (PA) is one of the most critical blocks in the transceiver and innovative PA architectures, which utilize such multidisciplinary techniques to improve output power, efficiency, gain, and linearity, will be discussed in this presentation. Novel topologies of digitally enhanced outphasing and pulse width modulated (PWM) PAs in 45nm CMOS at 2.4GHz will be presented. An innovative 74GHz stacked segmented adaptive PA architecture in 22nm FD-SOI technology will be shown next. Then an InP based 130GHz PA will be presented that can take advantage of III-V and CMOS co-integration for 6G wireless communication. Finally, future directions and research opportunities will be discussed. Co-sponsored by: IEEE AP-MTTS SBC IIT Kharagpur Speaker(s): Aritra Banerjee, Room: NKN Room, Bldg: E&ECE Department, Kharagpur, West Bengal, India, IIT Kharagpur, Kharagpur, West Bengal, India, 721302