InP HBT digital ICs and MMICs in the 140-220 GHz band

Well-balanced InP HBTs now have /spl sim/450 GHz cutoff frequencies and /spl sim/4 V breakdown. With such devices, 150 GHz digital circuits (static dividers) and 175 GHz amplifiers have been demonstrated. We discuss device requirements (scaling laws and scaling limits) for realizing transistors and both digital and analog/RF circuits at sub-mm-wave frequencies; the most critical limitations are metal/semiconductor contact resistivities and dissipated power densities. Given present contact performance and thermal design, 200 GHz digital technologies and 300 GHz power amplifiers are now feasible and will soon be realized.