This paper reviews and discusses our recent work on future integration strategies of millimeter-wave (mmW) and terahertz (THz) systems-on-chip. Our effort is mainly centered on the development of highly original and innovative architectural integration approaches in connection with the implementation of multifunction, low-power, high-efficiency, compact, and densely-integrated and topologically cohabitated front-end modules. Based on well-established low-cost CMOS processes such as 65-nm in our work, prototypes have been developed for numerous applications. Our battery-free, yet active mmW identification technology was demonstrated for the first time. An ultra-low-power MIMO receiver without LO was also studied and realized. An unprecedented unified and integrated front-end at 146 GHz, with amplifiers and antennas cohabitating in a shared-space manner, has been proposed theoretically and experimentally, suggesting a future development path of multifunction THz systems-on-chips through the deep integration of silicon ICs.