A Low-Power and High-Gain Mixer for UWB Systems

This letter presents a CMOS double-balanced direct-conversion mixer for ultra-wideband systems. The proposed mixer employs three techniques: the subthreshold operation of transistors for the radio frequency stage reduces current dissipation in the overall mixer, a local oscillation (LO) stage using an inverter lowers the required LO amplitude, and an active load improves conversion gain. The mixer was implemented using a 0.13 $mu{rm m}$ 1P8M CMOS process and was operated from 3.1 to 10.6 GHz. The measured results show a high conversion gain of 14.0 dB and a noise figure of 14.5 dB. In addition, the mixer performs with an input $IP_{3}$ of $-$ 11 dBm and a power dissipation of 1.85 mW from a 1.2 V supply.