Linearity Enhancement of a Fully Integrated 6-GHz GaN Power Amplifier

A large-signal nonlinearity compensation technique is developed to improve the linearity of RF GaN power amplifiers. The design of a high power amplifier employing both common-source (CS) and common-gate (CG) GaN high-electron mobility transistors is presented for the IEEE 802.11p standard. The power amplifier is fabricated in 0.25-μm GaNon-SiC technology and occupies 1.7 mm × 1.2 mm. The measurements show that 35-dBm output 1-dB compression point (OP1 dB) is obtained with 39-dBm OIP3 for two-tone intermodulation distortion testing. It also achieves 31% drain efficiency at 28.8-dBm output power with 10-V supply voltage considering a more than 6-dB back-off for orthogonal frequency division multiplexing-modulated signals. Linearity enhancement by means of the proposed CS-CG configuration is demonstrated in a fully integrated GaN power amplifier at 6 GHz.