Analysis and design of multi-stage wideband LNA using simultaneously noise and impedance matching method. (April 2019) - Sabzi, M.
Abstract: An analytical approach for design optimization of multi-stage LNAs with common source topology is developed. This paper reviews and analyses simultaneous noise and input impedance matching in three different topologies including common source amplifier with inductive degeneration, resistive feedback and dual feedback in order to achieve maximum available gain and minimum possible noise figure (NF). A study on multi-stage LNAs is performed to calculate optimum input impedance of each stage for minimum overall NF while considering the gain and NF of that stage in addition to the effect of noise of the following stages. MATLAB was used to calculate the starting point of design optimization in a multi-stage LNA. The proposed LNA in 0.1-μm GaAs pHEMT process exhibits a gain of 28 dB in the bandwidth of 3 GHz, input impedance matching of −14 dB, output impedance matching of −12 dB and 1-dB gain compression point of 10 dBm.