Finite element modeling of a MMIC transmitter module for thermal/structural design optimization

The complex mechanical design of a MMIC (microwave/millimeter wave monolithic integrated circuit) transmitter module and successful integration of it into a higher assembly required that a comprehensive mechanical analytical approach be adopted. This was accomplished by designing and constructing an integrated thermal/structural finite element model of the module and the assembly. The thermal model consisted of a 3200-element primary model with a supplemental model of the output FET region, containing another 5000 elements. A structural version of the primary thermal model performed the structural analyses. A key feature of the model construction and use was the internal coupling of the primary and supplemental thermal models and the structural models, eliminating manual interfacing and approximations which should improve accuracy and speed