Experimental investigation on wideband intermodulation distortion compensation characteristics of 3.5-GHz band 140-W class feed-forward power amplifier employing GaN HEMTs

This paper presents an experimental investigation on the wideband intermodulation distortion compensation characteristics of a 3.5-GHz feed-forward power amplifier for mobile base stations. The fabricated 3.5-GHz band 140-W class feed-forward power amplifier employing gallium nitride high electron mobility transistors (GaN HEMTs) achieves the intermodulation distortion compensation bandwidth of 160 MHz at the output power of 12.5 W and the adjacent channel leakage power ratio of -45 dBc using a long term evolution test signal with the bandwidth of 5 MHz. The results confirm that the feed-forward power amplifier with GaN HEMTs is a worthwhile linearizer because it offers wideband intermodulation distortion compensation performance to 3.5-GHz band mobile base stations.