High gain CMOS UWB LNA employing thermal noise cancellation

This paper presents a 3.1-10.6 GHz CMOS LNA designed with a 0.18 mum CMOS technology. In this amplifier, cancellation of two important noise sources in the amplifier, plus increasing effective transconductance of the input stage, reduce the noise figure (NF) of the amplifier. Noise canceling LNAs suffer from relatively low power gain. In contrast, this paper presents an ultra-wideband LNA with higher gain which also has better noise figure and lower power consumption achieved by utilizing gm-boosting technique and a modified form of noise cancelling technique. Also, bridged-shunt-series and asymmetric T-coil peaking techniques are employed to extend the bandwidth of the amplifier. The optimum values of all elements are determined using genetic algorithms. The proposed LNA achieves 17.5plusmn1 dB power gain and 2.25 dB average noise figure in the frequency range of 3.1-10.6 GHz, with 10.6 mW power drawn from a 1.8 V supply. Within the target band, input and output return losses are respectively less than -17 dB and -12 dB.