Optimisation of GaInP/GaAs HBT structures for high power operation at X-band and extraction of non linear electrical circuits for CAD

2D and 1 D hydrodynamic non stationary models of HBT's have been developed and used for the optimisation of GaInP/GaAs HBT structures for high power amplification at X band. These physical models can be coupled to the circuit either in the time domain or using an harmonic balance procedure. Linear and non linear electrical circuits of these devices were also extracted from the physical simulation results. This approach allows a good understanding of the main physical phenomena and an accurate description of the electrical parameters as a function of the various bias conditions and operating temperature.