Highly linear broadband GaN power amplifier design

In this paper, a 1 MHz to 3.4 GHz, 5 W, highly linear power amplifier based on GaN HEMT is reported. Load-pull technique has been applied to introduce a compromising solution for the PA performance trade-off problem. Over the whole bandwidth a small signal gain of 14 plusmn 0.7 dB and an output return loss of better than - 10 dB have been achieved. The input return loss was better than -10 dB up to 3 GHz. Power and linearity performances have been measured and compared to simulations resulting in a very good agreement. At a frequency spacing of 100 kHz, minimum values of output IP3 and output IP2 have been evaluated and found to be 48.5 dBm and 59.3 dBm. At 1 dB power compression point, minimum P_out and G_p were found to be ges 37.3 dBm and ges 13.3 dB, respectively within the whole frequency band.