A two-stage 0.9–2 GHz GaN power amplifier using commensurate transmission line

摘要

An semi-analytic method is proposed to reduce the complexity of two-stage matching network (MN). It is also improved by adding a variable in the power supply branch for cutting down the size of MN. The first stage operates in a deep class AB mode, which would contribute to reshape the voltage form at gate of the second stage. In this way, the two-stage power amplifier without isolator could also achieve a good gain and efficiency performance. The experimental results show that the large signal gain is 31.3-35.5 dB with output power of 39.2-41.9 dBm in the band of 0.9-2 GHz and corresponding drain efficiency is 37.4-62%. And linearity performance is also evaluated via stimulus of 5 MHz WCDMA and 20 MHz LTE signals.