54% PAE, 70-W X-Band GaN MMIC Power Amplifier With Individual Source via Structure

This letter reports on the development of an X-band GaN monolithic microwave integrated circuit (MMIC) high-power amplifier (HPA) which achieves a power-added efficiency (PAE) of 54% and an output power of 70 W. Mitsubishi's GaN field-effect transistors (FETs) with a gate length of 0.15 μm and individual source via (ISV) structure are utilized. The developed GaN MMIC HPA demonstrates an output power of 46.1-47.4 dBm (41-56 W), a PAE of 49-55%, and a gain of 10.1-11.0 dB at the frequency range 8.5-10.5 GHz with a drain voltage of 30 V. Output power of 47.2-48.4 dBm (53-70 W), PAE of 52%-54%, and gain of 11.2-12.1 dB at the frequency of 8.5-10.5 GHz are obtained with a drain voltage of 35 V. The measured performances demonstrate the highest performance in terms of the combinations of output power and PAE compared to existing state-of-the-art X-band MMIC HPAs.