X-band GaN MMIC power amplifier for the SSPA of a SAR system

An X-band monolithic microwave integrated circuit (MMIC) power amplifier for Synthetic Aperture Radar (SAR) systems has been implemented using a 0.25 μm AlGaN/GaN HEMT process on a SiC substrate. The MMIC power amplifier has an output power of 45 dBm (30 W) to 46 dBm (40 W) and a power-added efficiency of 38–44 % from 8.8 to 10.4 GHz with an associated power gain of 17 dB under the pulsed bias condition of a 10% duty cycle and 100 μs pulse width. The developed MMIC power amplifier will be applied to the solid-state power amplifier (sSPA) for future satellite SAR systems.