Active inductor based differential Low Noise Amplifier for ultra wide band applications

In this paper an Active Inductor (AI) based three stage Low Noise Amplifier (LNA) with Asymmetric T Coil peaking is presented. Asymmetric T coil peaking is used to provide wide bandwidth over the entire UWB range. Inductive source degeneration has been utilized in order to obtain a wide input matching and low noise figure. AI has been employed because of its low area, tunable inductance and high quality factor when compared with their spiral counterparts. The proposed LNA is designed using 90nm CMOS technology. This LNA achieves power gain (S₂₁) greater than 17dB throughout the UWB spectrum providing a maximum gain of 21dB at 5.5GHz with 3-dB bandwidth of 3.5 - 11 GHz. The input matching (S₁₁) and output matching (S₂₂) are kept well below -12 dB and -8dB respectively, while the reverse isolation (S₁₂) is less than -46 dB. The noise figure of this design falls in the range 4.1-7.6dB.