Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia Electrotécnica e de ComputadoresIn this thesis a MOSFET-only implementation of a balun LNA is presended. This LNA is
based on the combination of a common-gate and a common-source stage with canceling of
the noise of the common-gate stage. In this circuit, resistors are replaced by transistors,
to reduce area and cost, and minimize the e ect of process and supply variations and
mismatches. In addition we obtain a higher gain for the same voltage drop. Thus, the
LNA gain is optimized, and the noise gure(NF) is reduced. We derive equations for
the gain, input matching, and NF. The performance of this new topology is compared
with that of a conventional LNA with resistors. Simulation results with a 130 nm CMOS
technology show that we obtain a balun LNA with a peak 20.2 dB gain (about 2 dB
improvement), and a spot NF lower than 2.4 dB. The total power consumption is only
4.8 mW for a bandwidth wide than 5 GHz
