A CMOS direct-conversion I/Q up-mixer block for ultra-wideband system

This paper presents a direct-conversion I/Q up-mixer block, which is implemented in 0.18 mum CMOS technology, for the ultra-wideband (UWB) system. To achieve wideband characteristics, a shunt-peaking load is used in the up-mixer. A new wideband amplifier is also proposed, which can suppress unwanted common-mode signals with high linearity. The simulation results show gain flatness of less than 0.5 dB for three channels, a maximum output power level of -4.3 dBm, and a sideband rejection ratio of more than 60 dBc. The current consumption of this design is 27 mA from a 1.8 V power supply