A 4–10.6 GHZ low power LNA with dual reactive feedback and very low noise figure

A wideband low-noise amplifier (LNA) based on dual reactive feedback configuration and thermal noise canceling is proposed. The flat gain and wideband input impedance matching are achieved by using two reactive feedbacks. By adding an inductor at the source of the input transistor, a noiseless resistance for matching the input stage to source impedance is generated. The effect of cgd, in second stage, is improved by adding an inductor between gate and drain. Theoretical analysis shows that this LNA has a flat gain, low noise figure and good input impedance matching. The LNA is simulated in Agilent Technologies Advanced Design System (ADS). The noise figure is below 2dB and S
₁₁
and S
₂₂
are below -10dB. Also the minimum power gain (S
₂₁
) is 10.5 dB. The LNA draws 5.6mA from a 1V supply and the power consumption is 5.1 mW.