A high efficiency fully-monolithic 2-stage C-band GaN power amplifier for 5G microcell applications

A highly efficient two-stage 6 GHz fully-integrated GaN power amplifier (PA) designed for 5G microcell communication is reported in this work. Post-layout SPICE simulations show this two-stage PA achieves an output 1 dB compression Pout, idb above 33 dBm and greater than 31 dB gain and 34% PAE (power-added efficiency) for CW operation at 6 GHz. When the PA is driven with 5/10/20 MHz LTE 16QAM modulated signals, the simulated output spectra and adjacent channel leakage ratio (ACLR) at 4 dB below P
_{out, 1db}
passed the LTE spectrum emission mask (SEM) without any predistortion. Operated at a 28 V supply, this fully monolithic PA achieves reasonable frequency performance and linearity while it did not adopt the Doherty architecture for backoff efficiency enhancement; however, simulations suggest it may deliver good PAE values at power backoff when supply modulation is used to make it competitive for 5G PA microcell applications.