9629643 Prasad The major objective of this research project is the linearity and thermal stability characterization of the heterojunction biopolar transistor (HBT) for optimum performance. Experiments are to be performed using several devices of different geometries and material systems to be provided by the industrial collaborators. A preliminary investigation has resulted in the development of a large signal model of the inverted (collector-up) HBT for harmonic distortion analysis. This model is to be used to model intermodulation distortion using different methods such as Volterra series method of Maas and the nonlinear integral method of Filicori. Analytical and numerical methods are also proposed to be developed for the intermodulation distortion modelling. Power efficiency is to be investigated and optimum conditions for the most efficient operation are to be determined. In particular, the maximum power that the device can carry for efficient operation over a range of bias levels will be measured. Application specific optimization of the HBT for linearity and thermal stability should be the result of this research project. If successful, the same methods could be applied for the optimization of other applications. ***
