A 10-W6-12GHz GaN MMIC Supply Modulated Power Amplifier

This paper presents a gallium nitride (GaN) Monolithic Microwave Integrated Circuit (MMIC) PA with octave bandwidth, designed specifically for amplifying high peak-to-average power ratio (PAPR) signals with high efficiency from 6 to 12 GHz. Across the octave bandwidth, greater than 23.0% PAE is achievable over 10-dB of back off power using a dynamic supply voltage range from 6 to 20 V. We present the design and CW characterization of the PA as well as measurements using a 10-MHz multi-carrier noise-like signal and a 4-level discrete supply modulator comparing four different tracking functions. At 6.5 GHz a flat-gain, uniform voltage spacing function yields a 2.5 dB improvement in noise power ratio (NPR) over the static 20 V results with 3.8% points of PAE improvement, reaching 35.0 dBm of average output power. Furthermore, for a target NPR of 20 dB supply modulation yields a 9.7,% point improvement in PAE over the static case with a 1.5 dB increased output power.