Behavioral Electro-thermal Modeling of Power Amplifier for System-Level Design

This paper focuses on the behavioral modeling of thermal effects induced by power amplifier (PA) for system level simulation, in order to allow a better prediction of the link budget of RF transmitters for narrow band radar applications. A time behavioral modeling approach based both on X-parameters model [1] parameterized with temperature and 3D thermal simulations of the layout and packaging [2] has already shown a successful modeling of large mismatch under pulse radar excitation. In this work, we addressed the issue of thermal impedance ($\text{Z}_{\mbox {TH}} )$ evaluation by other means when information at technological level is missing. This first study was carried out through simulations on a GaN HEMT power transistor in which all of the relevant information is directly available and easily accessible.