X-Band outphasing power amplifier with internal load modulation measurements

This paper presents a general measurement based design method for outphasing amplifiers. Both isolated and non-isolated combiners are designed based on individual PA load-pull measurements, in order to load modulate two 0.15μm GaN MMIC power amplifiers at 10.1 GHz. Load modulation measurements are performed at ports internal to the PA, with the inclusion of couplers in the combiner and a four-port LSNA, to gain insight into the dynamics of load modulation during outphasing operation. Both outphasing systems exhibit a peak PAE greater than 41.5% at a peak output power greater than 35.7 dBm.