Bias Dependence Noise Modeling of Heterojunction Bipolar Transistors

Compact Software Inc., a leading software company in development of CAD tools for the microwave industry is proposing to develop a much needed bias-dependent noise model for Heterojunction Bipolar Transistors (HBTs). HBTs are viable candidates for future applications in monolithic microwave integrated circuits (MMICs) where highly accurate linear and non-linear noise models are critical, especially for first pass design. The noise models in use today are based on approximations which disqualify them for use with HBTs. Therefore a need exists for the development of an accurate physics-based HBT noise model which removes the current limitations. Our proposed model, is based on a full treatment of shot noise theory in semiconductor junctions, eliminating the current approximations. For model validation, we will obtain HBTs from several MIMIC foundries and will use "on wafer" noise characterization to obtain accurate noise parameters as function of frequency. During the Phase II program, we will complete the bias-dependent noise models for both shot noise and flicker noise and integrate the proposed models in our commercilly available circuit simulators, Microwave Harmonica and Super-Compact. The CAD enhancements resulting from this effort will be of immediate benefit to the MIMIC community and also to the DoD, MIC, MMIC suppliers and commercial microwave companies.