A 3～5 GHz UWB Up-Mixer Block Using 0.18-μm CMOS Technology

This paper presents a direct-conversion I/Q up-mixer block, which supports 3～5 GHz ultra-wideband(UWB) applications. It consists of a VI converter, a double-balanced mixer, a RF amplifier, and a differential-to-single signal converter. To achieve wideband characteristics over 3～5 GHz frequency range, the double-balanced mixer adopts a shunt-peaking load. The proposed RF amplifier can suppress unwanted common-mode input signals with high linearity. The proposed direct-conversion I/Q up-mixer block is implemented using 0.18 μm CMOS technology. The measured results for three channels show a power gain of —2～—9 dB with a gain flatness of 1 dB, a maximum output power level of —7～—14.5 dBm, and a output return loss of more than —8.8 dB. The current consumption of the fabricated chip is 25.2 mA from a 1.8 V power supply.