A 4–10 GHz fully-integrated stacked GaAs pHEMT power amplifier

A 4–10 GHz fully-integrated power amplifier (PA) is demonstrated using a 0.15-μm GaAs pHEMT process. This PA employs a compact structure with 4-parallel 3-stacked-FET cells to obtain a broadband power performance within a very small chip size. The measurement results of this PA in the frequency range of 4–10 GHz show a gain flatness of 13.5±1.5 dB, a maximum input return loss (S11) of −9 dB, a maximum output return loss (S22) of −7 dB, and a 35–37 dBm output power with the corresponding power added efficiency (PAE) of 25–32%. To the author's knowledge, this is the first GaAs PA ever reported which covers the frequency range of 4–10 GHz and achieves the combination of output power and instantaneous broadband performance within a chip size of 1.6×1.6 mm2.