Temperature Scalable SPICE Model for Kink Effect in GaN HEMTs for High-Power Applications

The kink effect in GaN (Gallium Nitride) High Electron Mobility Transistors (HEMTs) arises from trap-related device behaviors, leading to a sudden increase in drain current in the output (I<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</inf>–V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</inf>) characteristics. Accurate modeling of this effect is essential for reliable circuit design. While previous models based on the Advance SPICE Model (ASM) HEMT framework capture the kink effect, they have limitations in temperature scalability. This work presents an improved ASM-HEMT model with temperature-dependent parameters, enabling accurate prediction of kink onset from −40°C to 150°C. The model, implemented in Verilog-A and validated against both DC and load-pull measurements, demonstrates high accuracy across the wide temperature range, making it suitable for GaN circuit simulation under dynamic thermal conditions.