A 2.4 GHz low power folded down-conversion quadrature mixer in 0.18-μm CMOS

This paper describes a 1.8-V I/Q down mixer operating in 2.4GHz band for the Wireless Sensor Network (WSN) application using TSMC 0.18-μm RF CMOS process. The double-balanced mixer is modified based on the conventional Gilbert cell. It is composed of I/Q shared transconductance stage, folded switching stage, nMOS load stage, and common-mode feedback (CMFB) circuits. The mixer achieves a conversion gain of 13.84 dB with an input 1-dB compression point (IP_1dB) of -3.66 dBm. It also achieves a single side band (SSB) noise figure (NF) of 11.55 dB. The mixer acquires the third order input referred intercept point (IIP3) of 2.16 dBm. It consumes 1.96 mA of current from a 1.8-V power supply.