Abstract: A zero IF receiving front-end with merged LNA and mixer is proposed.Low flicker noise is achieved by decreasing bias current of switching pairs of folded architecture,with high gain as well.DC offset is improved by common and differential mode feedbacks,making the IF output level stable.High IIP2 is obtained by differential circuits'architecture and optimized layout.Spectre-RF simulations based on Chartered 0.18 μm CMOS process indicate that the presented receiving front-end behaviors good performance in noise,DC offset,and etc.Power consumption of the chip is 16.5 mW with size of that being 0.23 mm².