Design of Concurrent Low-Noise Amplifier for Multi-Band Applications

A concurrent multi-band low-noise amplifier (LNA) for both WLAN and WiMAX applications covering 2.4-2.7 GHz, 3.3-3.8 GHz and 5.1-5.9 GHz is mainly investigated. The proposed LNA consists of two cascaded common-source stages and employs stepped-impedance transformers and series and shunt feedback techniques to obtain good return loss, low noise and high linearity simultaneously. Test results show that the LNA features input and output return loss of 12 dB, gain of 21 dB, and noise figure of 2\,dB across the three bands of operation, which are the state of the art among the counterparts.