Low level and high linearity amplifiers in integrated technologies for satellite receivers: Technical issues of linearization techniques

Based on carrier to third intermodulation ratio (C/I3), reverse engineering of a two stages low level amplifier has been made in order to access the current transistor nonlinear models. Comparisons between two models of HEMT have been performed in order to choose the one which represent accurately weak nonlinearities at low level power dynamic range. By judicious choice of bias point, 12 dB improvement of linearity has been achieved. Other issues of linearization techniques have been studied so that to be suitable for MMIC implementation.