Assessing GaN FET Performance Degradation in Power Amplifiers for Pulsed Radar Systems

GaN FETs have achieved superior performance in the design of microwave power circuits. Nevertheless, the amount of dispersion related to this technology poses severe issues for the correct modeling and characterization of these devices. In this letter, the effects of GaN FET dispersion on the design of power amplifiers (PAs) with dynamic power supply, largely adopted in state-of-the-art high-efficiency pulsed radar transmitters, are discussed. In particular, we propose a technique for evaluating GaN device performance degradation in new-generation PAs that represents an effective alternative to pulsed-RF multiharmonic source/load-pull microwave setups.