Thermal transient analysis of GaN-based HEMTs based on spectral-element method

This paper shows a practical approach to GaN-based HEMT self-consistent electro-thermal simulation based on spectral-element method (SEM). The method is proposed to solve the heat transport equation in GaN-Based HEMTs. The high-order basis functions employed are orthogonal, leading to a diagonal mass matrix and a more sparse stiffness matrix. So the updating of thermal field is fully explicit when a forward difference scheme is employed for the time discretization. Examples of GaN-Based HEMTs, the thermal accumulation effects under the impact of a periodic input voltage signal are investigated with different drain voltage conditions, different substrates. Numerical results show that the SEM is an efficient alternative to conventional FEM and to the finite difference method (FDM) for microwave device thermal effect simulation.