Design and analysis of low noise amplifier at 60 GHz using active feedback and current re-use topologies

The design and analysis of low power, low noise amplifier (LNA) using active feedback and current re-use topologies at 60 GHz have been attempted in this paper. A single stage, basic cascode LNA is designed and its small signal gain is analyzed. To improve small signal gain, simple active transistor feedback and cascode feedback structures are designed and added to the basic LNA. In addition to this, current re-use inductor is designed and added to the cascode amplifier which is intended to give low power and low noise figure. Small signal analysis of simple active transistor feedback and current re-use inductor has been presented. The results of three LNAs included with simple active transistor feedback, cascode feedback and current re-use inductor are analyzed. It is observed that the gain increases approximately by 21.4 %, 35.76 % and 50.1 % for LNA circuits with active transistor feedback, cascode feedback and current re-use topologies respectively when compared to basic cascode LNA. Noise figures of the above mentioned topologies are observed to be 1.1 dB, 1.15 dB and 46.1e-03 dB respectively and found to be promising when compared to basic structure which gives 1.87 dB. Power consumption of the above mentioned circuits are nearly equal to 7.14 mW.