GaAs HBT power amplifier for WiBro applications

In this work, we report, for the first time, a 3.5 V class AB GaAs HBT power amplifier for WiMax/WiBro applications. The amplifier has 3 amplification stages to meet the gain requirement. It is class AB design to achieve both high linearity and efficiency. At 2.35 GHz with Vcc=3.5 V, the amplifier deliveries 25 dBm linear power to the load with 28 dB of gain and 20% of efficiency. Driven by OFDM signal consisting of 256 carriers with 16 QAM modulation the amplifier showed Error Vector Magnitude (EVM) of less than 3.5%, which meets the linearity specification of WiBro.