Improvement of power efficiency and cost reduction solution in microwave linear power amplifier

Power amplifier project covers an important role in microwave system design. In today´s 2G systems, when very complex modulation schemes, such 32, 64 and 128 QAM, are used, the handset power amplifier (PA) can consume as much as 75% of the battery power while transmitting, severely limiting battery lifetime. Moreover, the linearity of the transmission is dependent on the linearity of the PA. We have investigated the use of an envelope power reduction system plus an intermediate frequency large hand linearizer to simultaneously achieve efficiency, linearity and power consumption reduction in high power RF PAS. Another important note is that these improvements have been focused on a low cost circuit approach.