A 60-GHz 90-nm CMOS cascode amplifier with interstage matching

The design of a 60 GHz cascode amplifier in a 90 nm technology is described. The amplifier uses an interstage matching to increase the gain and to provide a better power match between the common-source and the common-gate transistor of the cascode device. Both the common-source and the common-gate transistor make use of an optimized round-table layout, which minimizes all terminal resistances and thus improves the mm-wave performance of the nMOS transistors. A record fmax of 300 GHz is achieved for a 40 mum round-table nMOS in 90 nm CMOS. The cascode amplifier achieves a gain of 7.5 dB at 60 GHz with a DC power consumption of only 6.7 mW. When compared to a shared-junction cascode amplifier or a two-stage common-source cascade amplifier, the presented cascode amplifier is favorable in terms of power gain and DC power consumption