Linearização de amplificadores de RF, pela combinação das técnicas de pré-distorção e alimentação direta

Abstract

Abstract: The linearization of power amplifiers in RF used in the transmission of analog and digital signals is one of the segments that has evolved considerably in recent years. Keep adjacent channels with low spurious constituted by harmonic distortion and the intermodulation products is one of the great challenges of electronic engineering applied to telecommunications. Spurious signals are from the intrinsic nonlinearity in any semiconductor device excited by large signs. Various techniques have been used, but the combination of the pre-distortion with direct feed (feed-forward) is quite promising. Whereas more stringent specifications are imposed by regulators for the transmission of digital TV, the design of power amplifiers effectively linearized will be one of the major obstacles to be overcome by the designers in our country. This work presents a comparative study of the various linearization techniques based on numerical simulations supported by the software "Advanced Design System", Agilent Technologies and programs developed in Matlab. It is shown that the combination of techniques, pre-distortion and direct power, offers a promising alternative to implement linearizadores high efficiency. The work also contributes derived mathematical models of the basic theme of these two linearization techniques which are suitable for its numerical simulation