Abstract: A differential lower noise amplifier (LNA) for wireless local network (WLAN) in front-end receiver is presented, which is fabricated with a JAZZ 0.35 μm 1P4M SiGe BiCMOS process. It can not only reject the common-mode noise signal in input port and but also depress circuit noise for using cascade topology, and realize its high performance. The LNA provides effectively a 50 Ωinput impedance matching and good temperature characteristic. At 2.5 GHz, the LNA exhibits a maximum small signal voltage gain of 29.1 dB, noise figure of 1.3 dB, input/output return loss better than -11 dB, and input IIP3 of -0.24 dBm, respectively. The LNA consumes 3.7 mA from a 3.0V DC supply. The simulation results show that, in comparison with the other LNAs, this LNA has higher voltage gain, lower noise and more efficaciously be utilized in WLAN and related fields.