A C-Band AlGaN-GaN MMIC HPA for SAR

A C-Band MMIC high power amplifier (HPA) has been designed exploiting a 0.25 μm HEMT GaN process on SiC substrate. The HPA is designed for future synthetic aperture radar (SAR) antenna applications. The HPA delivers 16 W output power with PAE over 38% at 6 dB gain compression within a 900 MHz bandwidth around 5.75 GHz. Up to 20 W output power and 40% PAE are obtained at higher gain compression. A comparison with another amplifier, differing only for the layout of the devices in the final stage, points out that the transistor thermal conditions represent the main limitation for this high power density technology.