Broadband Fully Integrated GaN Power Amplifier With Embedded Minimum Inductor Bandpass Filter and AM-PM Compensation

In this paper, we present a design technique for broadband linearized fully integrated GaN power amplifiers (PAs). The minimum inductor bandpass filter structure is used as the output matching network to achieve low loss and high out-of-band attenuation. Two parallel transistors with unbalanced gate biases are used to mitigate nonlinearity of their transconductance and input capacitance, and consequently, compensate AM-PM distortion of the PA. A fully integrated GaN PA prototype provides 35.1–38.9 dBm output power and 40-55% power-added efficiency (PAE) in 2.0–4.0 GHz. For a 64-QAM signal with 8-dB peak-to-average power ratio (PAPR) and 100-MHz bandwidth at 2.4 GHz, average output power of 32.7 dBm and average PAE of 31% are measured with −30.2 dB error vector magnitude (EVM).