CMOS microwave and millimeter-wave ICs: The historical background

Fully integrated microwave IC's have been in development since the 1970s. The move in recent years to complex microwave and millimeter-wave CMOS subsystems has prompted a considerable activity which must proceed in light of past developments and discoveries. This paper offers a perspective on pre-CMOS experience with active microwave circuits on a chip, some of which operated at 60 GHz. While a market for millimeter-wave consumer devices has yet to mature, there is enough research at hand to show that millimeter-wave electronics are feasible in the 60 to 77 GHz in state-of-the-art CMOS technology. It seems likely-or at least so the thinking goes-that the very existence of functional CMOS electronics, even antennas, which can be integrated with digital signal processing should pry open applications that lay dormant because of high cost. But millimeter-wave CMOS is not a straightforward extrapolation of RF-CMOS circuit design; it is a different circuit approach altogether, with roots that run much deeper than RF-CMOS. It is my purpose here to bring to light some of this history.