A high efficiency 140W power amplifier based on a single GaN HEMT device for space applications in L-band

This paper deals with the design, manufacture and test of a high efficiency power amplifier for L-band space borne applications. The circuit operates with a single 36 mm gate periphery GaN HEMT power bar die allowing both improved integration and performance as compared with standard HPA design in a similar RF power range. A huge effort dedicated to the device´s characterization and modeling has eased the circuit optimization leaning on the multi-harmonics impedances synthesis. Test results demonstrate performance up to 140 W RF output power with an associated 60% PAE for a limited 3.9 dB gain compression under 50 V supply voltage using a single GaN power bar.