Thermal-aware GaN/Si MMIC design for space applications

Thermal stress in microwave power devices is a major issue for space applications, with a detrimental impact on the operating life-time of MMICs on board satellites. To limit this, derating rules are applied to the maximum operating junction temperature, which however limit the potential device performance when GaN/Si technology is employed. In this framework, classical power amplifier design paradigm must be reconsidered, moving to a thermal-aware design approach. To this aim, it is crucial to have access to highly reliable thermal models of the adopted devices. This work will show that, adopting a simplified but effective thermal model and proper design strategy, GaN/Si technology can be successfully adopted for space-compliant MMIC design up to Ka-band. In particular, the preliminary design of a 10W MMIC working in Ka-band at 36 GHz will be presented based on the 100nm gate-length GaN/Si HEMT process from OMMIC foundry.