Multi-physics modeling of high-power microwave transistors

In this paper, we present a multi-physics approach for the simulation of high-power microwave transistors in which electromagnetic, thermal, and nonlinear transistor models are linked together within a harmonic-balance circuit simulator. This approach is used to analyze an LDMOS transistor operating at 2.14 GHz. The total gate width of the die is 102 mm, and the die is placed in a ceramic package and connected using bond-wire arrays at gate and drain. The effects of three different gate bond-pad metallization on the transistor efficiency are studied. Plots of the spatial distribution of the drain efficiency, and time-domain current and voltage provide a unique insight and understanding of the behaviours induced by the different bond-pads.