A 3.1–10.6 GHz frequency tunable ultra wideband LNA

This paper presents an ultra-wideband (UWB) low noise amplifier (LNA) which is implemented with TSMC 0.18-μm CMOS process. In the proposed chip, both shunt-series feedback and bandpass filter are used to complete the input matching of the desired ultra broadband chip; and that the power consumption is reduced using the current reused method. Besides, not only the isolation of LNA is improved with a cascade amplifier, but also the output matching is achieved with buffer. Finally, a multiple gated circuit is added to improve the linearity. The simulation results of the proposed UWB LNA shows that the isolation, input return loss, output return loss, power consumption are -83 dB, -12.3 dB, -11.1 dB, and 12.2 mW, respectively; and that the power gain from 11.5 dB to 13.4 dB, gain flatness of 0.245, and noise figure from 3.8 dB to 4.7 dB are obtained at frequency bandwidth from 3.1 GHz to 10.6 GHz. Notify that the simulated P_1dB and IIP₃ are -11.25 dBm and -13.28 dBm, respectively, at frequency of 6 GHz.