A Low-Noise 2.5GHz Direct-Conversion Receiver Frond-End with Low-Distortion Baseband Filters

A 2.5 GHz direct conversion receiver front-end has a 3.2 dB DSB NF, -14 dBm IIP3, and +27 dBm IIP2, referred to the LNA input. The RFI/Q mixers are configured as Gm-cells interfacing to current-mode CMOS I/Q continuous-time elliptic filters. The filters can operate from a IV supply and achieve an average input noise current of 11.2 pA/sqrt(Hz), <3% tuning accuracy and <0.5% I/Q bandwidth matching. The receiver draws 30 mA from a 2.7 V supply. The chip is fabricated in a 0.5 mum 46 GHz f_T BiCMOS process. The active area is 2.54 mm².