A High-Linearity GaN-on-Si Power Amplifier for 2.4-GHz WLAN Applications

The high impedance of a GaN device when operating at high voltage and low current is more resilient to the loss caused by the on-chip inductor and makes a fully integrated GaN-on-Si power amplifier possible. This paper demonstrates a 2.4 GHz two-stage power amplifier for WLAN applications using low-cost GaN-on-Si technology with a high resistivity silicon substrate and through substrate vias. The high-linearity power amplifier at a 15 V supply voltage shows 22 dBm output power with -35 dB EVM at 2.5 GHz when tested with 802.11ac VHT40 MCS9 signals. The quiescent currents are 13 mA and 27 mA while the operating currents at 22 dBm output power with -35 dB EVM are 26 mA and 65 mA for the driver stage and power stage, respectively.