The paper represents a lowest noise ever high gain CMOS direct down-conversion mixer for 1.8 GHz applications, like GSM, PCS, etc., based on 0.18 /spl mu/m CMOS technology. The designed mixer uses the current bleeding technique and an extra inductor to improve the conversion gain and noise figure (NF). Also, with an extra inductor and the careful choosing of transistor sizes, the mixer has the lowest ever reported flicker noise. Simulation results show the voltage conversion gain of 28.2 dB, the single-side band (SSB) NF of 4.09 dB. Flicker noise cut-off frequency is just a few kHz. SSB NF at 50 Hz reaches 16.8 dB. The circuit operates at the supply voltage of 1.8 V, and dissipates 11.34 mW.