This paper presents a low voltage 2.8-11.2GHz CMOS broadband low noise amplifier (LNA) using folded common-gate (CG) topology. The broadband input matching is achieved by adopting CG topology. Bandwidth extension is proposed by inserting an inductor to create a broadband band-pass characteristic with a choke inductor. A folded topology is employed to reduce the supply voltage and thus power consumption. A source follower jointly acts as the buffer stage for broadband output impedance matching and feed-forward path for gain enhancement. Maximum power gain is 11.2dB and the NF ranges from 2.58 to 4dB over the full band. The LNA achieves an average IIP3 of -6.5dBm while consumes only 4.6mW.The proposed broadband LNA is designed in 0.18-µm CMOS process from 1V supply.