A low power UWB-LNA using active dual loop negative feedback in CMOS 0.13µm

A low noise amplifier for UWB and broadband applications is presented. The active dual loop negative feedback architecture dissevers the severe tradeoff existing between the input impedance, gain and noise figure, and produces a flat S₁₁ across the entire band. The LNA is composed of a voltage amplifying negative feedback amplifier with a transconductance amplifier forming a shunt-shunt feedback around it, thereby tailoring the input impedance with respect to the gain settings of the first amplifier. The values of the resistive feedback elements have been chosen such that they fulfill the requirements of gain, input impedance, noise figure and linearity. The design has been carried out in TSMC 0.13 mum CMOS technology. From circuit simulations, the average gain of the LNA across 2-7 GHz is 13 dB. The noise figure is below 4 dB with a minimum of 2.9 dB. S₁₁ is below -15 dB for the entire frequency band. The design employs a DC-current re-use scheme to reduce the power consumption. The LNA draws 5.6 mA from a 1.2 V supply.