A 0.8–3GHz wideband folded down-converter with noise cancellation in 0.18um SiGe technology

This paper proposes a wideband low-noise down converter with operational frequency ranging from 0.8-3GHz in 0.18μm SiGe technology. The down converter is based on a double balanced Gilbert cell configuration with folded structure to lower the supply voltage. The folded structure also allows separate bias for the mixer and the gm stages to optimizing their performances. Bipolar based gm cell with noise cancellation is employed to achieve low noise and wideband input matching. Measured results show average single-sideband noise figure of 6.5dB and conversion gain of 20.5 dB across the entire wide input bandwidth from 0.8~3GHz. The measured HP3 is around -5 dBm with 13.5mW power consumption under a 1.5V power supply. The wideband down-converter chip is implemented in 0.18nm SiGe technology with area of 2 mm².